KLRK1 and neoplasm: Collectively, a single local irradiation with 8 Gy was sufficient to enhance the antitumor effects of NKG2D CAR-T cells against ESCC xenografts, by effect of upregulating NKG2DL expression on the surface of tumor cells, as well as altering the TME, thereby promoting the migration and infiltration of NKG2D CAR-T cells into tumor sites.