In terms of geographical correlation between fibroblasts and gastroids, while αSMA+ cells from inflamed normal-derived fibroblasts were irregularly scattered between gastroids, several PDGFRα+, FBLN2+, and/or TGFBI+ cells from metaplasia- or cancer-derived fibroblasts directly contacted with gastroids (Figure 4E and Supplementary Figure 9A and B), similar to FbS1 and FbS2 that closely surrounded epithelial compartments in various preneoplastic lesions of human stomach (Figure 1F and Figure 2A–C). The gene discussed is PDGFRA; the disease is cancer.