Fibroblasts were classified into eight subgroups based on marker genes (Figure 3F,H,I; Figure S8, Supporting Information), using the classification framework for cancer‐associated fibroblasts.[34] AM lesions contained greater proportions of insulin‐like growth factor binding protein 2 (IGFBP2)‐, secreted frizzled‐related protein 4 (SFRP4)‐, and chitinase 3‐like 1 (CHI3L1)‐high‐expressing fibroblasts, consistent with qPCR verification (Figure 3H,J). Here, CHI3L1 is linked to cancer.