PDCD1 and colorectal carcinoma: In this retrospective study, we therefore aimed to explore the demographic (age, sex, alcohol consumption, and smoking), clinic-pathologic factors, and treatment outcomes in relation to the different subsets of ICs found in stage I to III CRC patients by using tissue microarrays (TMAs), computer-assisted imaging, and automatic counting to analyze the densities of immunostained clusters of differentiation (CD)3+, CD8+, CDRO45+, PD-1+, and PD-L1+ markers in intra-tumor ICs.