Additionally, cancer-associated fibroblasts, which are critically involved in tumor progression19, showed significantly positive correlation with PIK3R1 expression in BRCA, CESC, CHOL, COAD, ESCA, HNSC, LUAD, LUSC, PAAD, PRAD, STAD and TGCT, while observed a negative correlation in LGG (Fig. 6C). This evidence concerns the gene PIK3R1 and cancer.