STEAP4 and neoplasm: To elucidate the pivotal role of fibroblasts in shaping the PDAC microenvironment, we utilized previously reported fibroblast subtype-specific markers 4, 8, 21 and categorized 21,629 fibroblasts into eight clusters: RGS5+ fibroblasts, MYH11+ fibroblasts, STEAP4+ fibroblasts, C7+ fibroblasts, ECM-remodeling fibroblasts, Tumor-like fibroblasts, HLA-DRA+ fibroblasts and NRXN1+ fibroblasts (Figure 2A-B, Figure S3).