The spliceosome is a ribonucleoprotein complex involved in RNA splicing, that is, the removal of non-coding introns from precursor messenger RNA. (Alternative) Splicing events may play an essential role in tumourigenesis. The recent discovery that the spliceosome is a target for novel compounds with anticancer activity opens up new therapeutic avenues.British Journal of Cancer advance online publication, 25 November 2008; doi:10.1038/sj.bjc.6604801 www.bjcancer.com.