PTK2 and hepatocellular carcinoma: In hepatocellular carcinoma (HCC) tissues, macrophage showed an M2 polarization, and the in vitro study confirmed that a stiff matrix could strengthen the M2 polarization and induce LOXL2 expression through integrin β5-FAK-MEK1/2-ERK1/2 pathway (Xing et al., 2021).