AFP can bind to AFPRs and activate the cyclic adenosine 3’, 5’-monophosphate (cAMP)-protein kinase A (PKA) pathway and induce Ca2+ influx, which increases intracellular cAMP and PKA, enhances DNA synthesis, promotes the expression of the oncogenes c-fos, c-jun, and ras, and stimulates the growth of liver cancer cells (Figure 1) (10–12). Here, AFP is linked to liver cancer.