MAPK3 and liver cancer: We first selected the liver cancer HepG2 cells with the highest expression of BMPR-II from three liver cancer cell lines, then observed the changes in liver cancer cell’s invasion, proliferation, apoptosis and cell cycle after BMPR-II silence; and the changes in MAPK signal pathway-related proteins (p-P38, p-ERK1/2, p-JNK and VEGF-C) after BMPR-II silence, and BMPR-II silence combined with inhibiting MAPK signal pathway (with SB203580: P38 inhibitor, PD98059: ERK1/2 inhibitor and SP600125: JNK inhibitor, respectively).