PDCD1 and gastric cancer: Interestingly, TMEM200A was positively correlated with the expression of 12 immune checkpoints in GC (Figure 8C), such as PDCD1, TIGIT, LAG3, CD40, etc. The above results suggested that TMEM200A probably modulated the tumor immune microenvironment (TIME) of GC, promoted the infiltration of immune cells and upregulates the expression of various immune checkpoints, which helped GC cells to immune escape and thus promoted the progression of GC.