Conversely, CDK12 is co-amplified with the receptor tyrosine kinase (RTK) oncogene HER2 (also known as ERBB2) in many cases of breast cancer, where it promotes migration and invasion of tumor cells by downregulation of the nuclear isoform of DNAJB6 via alternative last exon splicing (15). The gene discussed is ERBB2; the disease is breast carcinoma.