We found that knockdown of PSMD3 in BT-474, SKBR3, and HCC-1419 cells led to decrease of the total form of HER2 and inhibition the main HER signaling pathways, p-AKT and p-ERK; however, no significant effect was observed for the un-transfected cells or cells transfected with the scrambled siRNA (Figure 3D). The gene discussed is ERBB2; the disease is hepatocellular carcinoma.