FAP and colorectal carcinoma: High IL1R1 mRNA expression in the tumor stroma compared to the epithelial compartment was also detectable in three additional public bulk CRC datasets, where stromal and epithelial cells were either isolated by fluorescence-activated cell sorting (FACS), based on FAP and EPCAM expression (Calon19), or by laser microdissection (Nishida20 and Rupp21,22) (Supplementary Fig. 1c).