MAPK1 and cancer: Expression of miR-199a/a* is silenced in all proliferating cell lines tested except fibroblasts; introduction of miR-199a/a* caused apoptosis in cancer cells; miR-199a* down-regulates MET proto-oncogene and also down-regulates ERK2, an effector downstream of MET (Additional file 2 and 3) [54].