To evaluate the ability of [99mTc]Tc-HYNIC-WL12-tricine/M (M = TPPTS, ISONIC, PDA, and 4-PSA) to target PD-L1, mouse colon cancer MC38 and human PD-L1 gene-transfected MC38 cells (MC38-B7H1) were used. The gene discussed is CD274; the disease is malignant colon neoplasm.