A total of 2217 cells were identified as fibroblasts, and mostly were tumor-derived (Figs. 5A and S3): fetal cluster (PLK2), cluster 1 (NDUFA4L2), cluster 2 (S100A8), and cluster 3 (THBS2) (Fig. 5A, B). This evidence concerns the gene COXFA4L2 and neoplasm.