CD274 and gastric cancer: Intriguingly, expression of the PD‐1 ligand PD‐L1 in mouse tumors was mainly found in the Sca‐1+ and/or CD49f+ epithelial compartment of BCC‐like lesions, suggesting cell‐autonomous induction of this immune inhibitory molecule in response to oncogenic Hh/Gli activation in epidermal cells (Fig. 2D), consistent with a recent study showing direct GLI‐mediated PD‐L1 activation in a murine organoid model of Gli2‐driven gastric cancer [59].