diff --git a/pipeline/download_gene.py b/pipeline/download_gene.py
index 54f09d7..a39336b 100644
--- a/pipeline/download_gene.py
+++ b/pipeline/download_gene.py
@@ -51,6 +51,14 @@ def parse_args():
         Path to output directory to save results.
         """,
     )
+    parser.add_argument(
+        "--downsample-ref",
+        type=int,
+        default=25,
+        help="""\
+        Downsampling factor of the reference space.
+        """,
+    )
     parser.add_argument(
         "--downsample-img",
         type=int,
@@ -79,6 +87,7 @@ def postprocess_dataset(
         None,
     ],
     n_images: int,
+    downsample_ref: int,
 ) -> Tuple[np.ndarray, np.ndarray, dict[str, Any]]:
     """Post process given dataset.
 
@@ -116,7 +125,7 @@ def postprocess_dataset(
             # TODO: maybe notify the user somehow?
             continue
 
-        section_numbers.append(section_coordinate // 25)
+        section_numbers.append(section_coordinate // downsample_ref)
         image_ids.append(img_id)
         warped_img = 255 - df.warp(img, border_mode="constant", c=img[0, 0, :].tolist())
         dataset_np.append(warped_img)
@@ -140,6 +149,7 @@ def postprocess_dataset(
 def main(
     experiment_id: int,
     output_dir: Path | str,
+    downsample_ref: int,
     downsample_img: int,
     expression: bool = True,
 ) -> int:
@@ -151,6 +161,10 @@ def main(
         Gene ID to download.
     output_dir
         Directory when results are going to be saved.
+    downsample_ref
+        Downscaling of the reference space grid. If set to 1 no
+        downsampling takes place. The higher the value the smaller the grid
+        in the reference space and the faster the matrix multiplication.
     downsample_img
         Downsampling factor given to Allen API when downloading the images.
         This factor is going to reduce the size.
@@ -174,19 +188,23 @@ def main(
 
     logger.info(f"Start downloading experiment ID {experiment_id}")
     dataset = DatasetDownloader(
-        experiment_id, downsample_img=downsample_img, include_expression=expression
+        experiment_id,
+        downsample_img=downsample_img,
+        include_expression=expression,
+        downsample_ref=downsample_ref,
     )
     dataset.fetch_metadata()
     dataset_gen = dataset.run()
     axis = CommonQueries.get_axis(experiment_id)
     dataset_np, expression_np, metadata_dict = postprocess_dataset(
-        dataset_gen, len(dataset)
+        dataset_gen, len(dataset), downsample_ref
     )
     metadata_dict["axis"] = axis
+    metadata_dict["downsample-ref"] = downsample_ref
 
     logger.info(f"Saving results of experiment ID {experiment_id}")
-    np.save(output_dir / f"{experiment_id}.npy", dataset_np)
-    with open(output_dir / f"{experiment_id}.json", "w") as f:
+    np.save(output_dir / f"{experiment_id}-{downsample_ref}.npy", dataset_np)
+    with open(output_dir / f"{experiment_id}-{downsample_ref}.json", "w") as f:
         json.dump(metadata_dict, f, indent=True, sort_keys=True)
 
     if expression_np is not None:
diff --git a/pipeline/gene_to_nissl.py b/pipeline/gene_to_nissl.py
index 046925b..e7a0804 100644
--- a/pipeline/gene_to_nissl.py
+++ b/pipeline/gene_to_nissl.py
@@ -111,7 +111,7 @@ def registration(
         except IndexError:
             logger.warn(
                 f"One of the gene slice has a section number ({section_number})"
-                f"out of nissl volume shape {nissl_volume.shape}. This slice is"
+                f"out of nissl volume shape {nissl_volume.shape}. This slice is "
                 "removed from the pipeline."
             )
             section_numbers_kept.append(False)
diff --git a/pipeline/interpolate_gene.py b/pipeline/interpolate_gene.py
index 82a0ee9..a27271c 100644
--- a/pipeline/interpolate_gene.py
+++ b/pipeline/interpolate_gene.py
@@ -153,11 +153,12 @@ def main(
     section_numbers = [int(s) for s in metadata["section_numbers"]]
     axis = metadata["axis"]
 
+    volume_shape = [num // metadata["downsample-ref"] for num in [13200, 8000, 11400]]
     # Wrap the data into a GeneDataset class
     gene_dataset = GeneDataset(
         section_images,
         section_numbers,
-        volume_shape=(528, 320, 456, 3),
+        volume_shape=(*volume_shape, 3),
         axis=axis,
     )
 
@@ -197,7 +198,7 @@ def main(
 
     np.save(
         output_dir
-        / f"{experiment_id}-{interpolator_name}-interpolated-{image_type}.npy",
+        / f"{experiment_id}-{metadata['downsample-ref']}-{interpolator_name}-interpolated-{image_type}.npy",
         predicted_volume,
     )
 
diff --git a/pipeline/nissl_to_ccfv3.py b/pipeline/nissl_to_ccfv3.py
index 7a9f8b8..c506a13 100644
--- a/pipeline/nissl_to_ccfv3.py
+++ b/pipeline/nissl_to_ccfv3.py
@@ -84,16 +84,28 @@ def registration(
         Nissl volume once the registration transformation are applied.
     """
     logger.info("Compute the registration...")
-    nii_data = register(reference_volume, moving_volume)
-    logger.info(f"Max displacements: {np.abs(nii_data).max(axis=(0, 1, 2, 3))}")
+    nissl_warped = []
+    warped_volume = []
 
-    logger.info("Apply transformation to Moving Volume...")
-    warped_volume = transform(moving_volume, nii_data, interpolator="genericLabel")
+    for i, (reference, moving, nissl) in enumerate(zip(reference_volume, moving_volume, nissl_volume)):
+        try:
+            nii_data = register(reference, moving)
+            logger.info(f"Max displacements: {np.abs(nii_data).max(axis=(0, 1, 2, 3))}")
 
-    logger.info("Apply transformation to Nissl Volume...")
-    nissl_warped = transform(nissl_volume, nii_data)
+            logger.info("Apply transformation to Moving Volume...")
+            warped_volume.append(transform(moving, nii_data, interpolator="genericLabel"))
 
-    return warped_volume, nissl_warped
+            logger.info("Apply transformation to Nissl Volume...")
+            nissl_warped.append(transform(nissl, nii_data))
+        except RuntimeError:
+            logger.info(f"Registration for slice {i} went wrong...")
+            warped_volume.append(moving)
+            nissl_warped.append(nissl)
+
+        if (i + 1) % 5 == 0:
+            logger.info(f" {i + 1} / {reference_volume.shape[0]} registrations done")
+
+    return np.array(warped_volume), np.array(nissl_warped)
 
 
 def main(