Later, some researchers define “AFPGC” as “immunohistochemical AFP positivity of tissues.” In 1981, Kodama et al. verified the expression of AFP in gastric cancer, through immunohistochemistry, and established the concept of “AFP-producing gastric cancer” [24] and some other researchers defined “AFPGC” as “positive of AFP in both serum and tissue” [17]. Here, AFP is linked to gastric cancer.