Our interest in minor splicing came with our discovery that the rnpc3 gene, which encodes a protein component of the minor spliceosome, is required for the rapid growth and proliferation of cells in the developing digestive organs of larval zebrafish. Further experiments indicated a heightened requirement for Rnpc3/minor splicing in tissues undergoing rapid, continuous cell cycling, compared to quiescent tissues. Current studies are directed towards determining whether minor splicing is an Achilles’ heel of all highly proliferative tissues, including cancer.