High throughput sequencing cross-linked immunoprecipitation (HITS-CLIP) and RIP-Chip CELF1 studies have identified CELF1 nucleotide recognition sequences and CELF1 associated mRNA targets [14, 17, 31, 32]; however, the CELF1 positively and negatively controlled mRNAs and the CELF1-mediated alternative splicing events in cancer remains to be determined. The gene discussed is CELF1; the disease is cancer.