An in vitro study showed that magnesium cantharidate has an inhibitory effect on the proliferation of SMMC-7721 human hepatoma cells by blocking the MAPK (mitogen-activated protein kinases) signaling pathway; the phosphorylation levels of C-jun N-terminal kinase (JNK) and extracellular signal-related kinase (ERK) decrease significantly after such treatment [31]. Here, MAPK8 is linked to hepatocellular carcinoma.