CD226 and colorectal carcinoma: Next, by focusing on tumor-associated PD-1+ tr-NK cells from MSI CRC patients, we found that the expression of activating receptors (NKp46, NKp30, NKp44, DNAM-1, NKG2D and CD16) was similar or only slightly lower on tumor-associated PD-1+ tr-NK cells from MSI CRCs compared to tumor-associated PD-1– tr-NK cells from both MSI and MSS CRCs.