CD274 and colorectal carcinoma: Ectopic CT45A1 expression in two MSI‐H CRC cell lines did not alter the surface expression of MHC‐I (Fig. S2A,B), PD‐L1 (Fig. S2C,D), or sialylated ligands for Siglec‐7 (Fig. S2E,F) or Siglec‐9 (Fig. S2G,H).