Mdm4: don't judge an isoform by its mRNA levels!

Alternative splicing of RNA precursors expands the coding capacity of the genome by allowing the production of protein isoforms of distinct and even opposing functions from a single gene. It may also constitute a major mechanism of gene expression regulation. Importantly, pathways frequently deregulated in cancer often play important roles in promoting aberrant splicing, which in turn could affect tumor development by modulating cell cycle control, apoptosis, metabolism, angiogenesis, invasion and metastasis [1].