PTK2 and neoplasm: Moreover, overexpression of ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 1 (ST8SIA1) can increase the tumor cell proliferation, migration, and invasion in prostate cancer, colorectal cancer, and breast cancer via the promotion of the FAK‐AKT‐mTOR signaling pathway [52, 54, 55].