The fact that an increased expression of angiogenesis-related genes as well as an upregulation of MAPK/ERK signaling is associated with sorafenib resistance 26, 27 led us to investigate the impact of miR-449a-5p and its target genes on the effect of sorafenib in hepatocellular carcinoma. The gene discussed is MAPK1; the disease is hepatocellular carcinoma.