CD274 and neoplasm: Co-high expression of tumor PD-L1 and CTLA-4 in CRC tissues is a negative predictor of OS (HR 3.86, 95% CI 1.71–8.51, p = 0.001 in the membrane-bound receptor form and HR 5.72, 95% CI 1.87–14.54, p = 0.004 in the soluble form), in addition to being an independent prognostic factor for poor disease-free survival [153].