The single-cell datasets used in this study can be accessed through the following links: (1) HER2+ and breast cancer: GEO accession: “GSE176078”; (2) cSCC: GEO accession: “GSE144236”; (3) liver cancer: GEO accession: “GSE125449”; (4) PAAD dataset: “GSE242230” The external validation on TCGA can be found in https://portal.gdc.cancer.gov/. Here, ERBB2 is linked to breast cancer.