Further screens have identified that flunarizine, a calcium channel blocker, can alter splicing events in HeLa cells, including intron retention in SMN.48 This was confirmed in a screen on SMA patient fibroblasts, where flunarizine increased localization of SMN to Cajal bodies and improved the survival of spinal cord motor neurons from SMA mice.50 This evidence concerns the gene SMN2 and proximal spinal muscular atrophy.