PDCD1 and colorectal cancer: According to clinical trial reports, the Food and Drug Administration (FDA) has approved reagents such as SP263 and 22C3 as companion diagnostics for PD-L1, and PD-1/PD-L1 immunotherapy combinations approved by the FDA have shown positive results in cancers like lung cancer, colorectal cancer, and triple negative breast cancer (TNBC) (Lee et al., 2020; Nobin et al., 2024; Savic et al., 2019).