MR1 and cancer: Due to its cancer promoting activity generated after translocation into the nucleus, we conducted cytoplasmic‐nuclear separation experiments, and found that the nuclear localization of NICD3 was decreased in H1299 cells with stably MR‐1‐knockdown, while H460 cells with stably MR‐1‐overexpression promoted the nuclear localization of NICD3 (Figure S5E, Supporting Information).