BMP4 and hepatocellular carcinoma: The simultaneous increase in cell proliferation and decrease in apoptosis elicited by ERK1/2 also induces resistance to different chemotherapeutic drugs in ovarian cancer, where ERK1/2 activates the pro-survival effectors mitogen activated kinase kinase (MKK) and eukaryotic translation initiation factor 4E (eIF4E) [20], in hepatocellular carcinoma, where ERK 1/2 is part of the bone-morphogenetic protein 4 (BMP4)-dependent signalling [98], and in colon cancer, where ERK1/2 cooperates with the pro-survival transcription factor NF-kB [99].