CT45A1 and colorectal carcinoma: We found that the expression of CT45A1 in these two MSI‐H CRC cell lines did not consistently affect cell viability (Fig. S1A), clonogenicity (Fig. S1B), epithelial–mesenchymal transition (EMT)‐related gene expression (Fig. S1C), Transwell motility (Fig. 2C,D), or stemness gene expression (Fig. S1D).