Third, although CD90+ cells co-stain for well-known markers of CAFs, αSMA and FAP, and we uncovered a strong positive correlative between THY1/CD90 gene expression and CAF gene signature across TCGA MPM tumor samples estimated by multiple immune deconvolution methods (EPIC, MCPcounter, or TIDE algorithms), it is still unclear whether CD90+ cells are a mesothelial precursor cell that has undergone epithelial-to-mesenchymal transition due to protracted exposure to TGFβ1 62 or a subset of CAFs previously described in MPM 8, 63. Here, FAP is linked to neoplasm.