In HEPG2 and MHC97l cancer cells, overexpression of mir-30a completely blocked the activation of the KRAS proto-oncogene, GTPase (KRAS)/ Raf-1 proto-oncogene, serine/threonine kinase (c-RAF)/MAPK/ERK kinase (MEK)/extracellular regulated kinase (ERK) pathway. The gene discussed is KRAS; the disease is cancer.