ACTA1 and colorectal carcinoma: IHC staining of an in-house CRC patient tissue microarray (TMA; n = 106, Supplementary Table 3) revealed a strong correlation of IL-1β with FAP expression (Fig. 2h), especially in CMS4 (Supplementary Fig. 3d), but not between IL-1β and αSMA expression (Fig. 2h, Supplementary Fig. 3d), further reinforcing the link between FAP-expressing CAFs and IL-1β.