CD274 and familial pancreatic carcinoma: Given that several previous studies have documented the direct and indirect regulatory effects of RTKs on ICPs, the most critical mediators for tumor immune resistance, we further analyzed the correlation between upregulated RTKs and representative ICPs (PD-L1, CD276, CD155, CD112, LGALS9, and HVEM) in pancreatic cancer and found that 16 RTKs significantly positively correlated with ICPs in terms of expression level (Fig. 2C and D).