AFP and neoplasm: AFP is used as a specific index for the screening and diagnosis of primary liver cancer and has many important biological functions, including as a growth regulating factor with a two-way adjustment function, regulating the expression of oncogenes, promoting the growth and proliferation of tumor cells, invasion and metastasis of autophagy, inhibiting tumor cell apoptosis, suppressing the activation of T cells and DC cells, inducing apoptosis of these cells, and thus escaping immune surveillance, further causing malignant cancer transformation (54–56).