The positivity rates of CA125 and CA199 are relatively low in early-stage gastric cancer (Feng et al., 2017), the positivity rates of CA199 and CA125 in stages III/IV gastric cancer are higher than those in stages I/II, and preoperative serum positivity for both is associated with poor prognosis; they can be utilized to predict recurrence or metastasis of gastric cancer (Zhou et al., 2018). Here, MUC16 is linked to gastric cancer.