CDK7 and breast cancer: In this study, by integrating CRISPR-CAS9 functional genomics (DEPMAP database) and TCGA multi-omics data, seven key genes (CDK7, CLTC, COPB2, CRNKL1, GSPT1, NSF and PSMD12) that are closely related to the proliferation and prognosis of breast cancer were systematically identified.