Though the MSI test has been the primary method to predict responses to PD1/PD-L1 therapies, recent clinical studies have found some CRC cases with MSI-H displayed unexpectedly ineffective to PD1/PD-L1 therapies due to inaccuracy or misinterpretation of the MSI-PCR test results before the treatments. The gene discussed is CD274; the disease is colorectal carcinoma.