Our previous report on the incidence of CDK4 overexpression/gene amplification in pancreatic NETs, combined with the response of PNET cell lines to CDK4/CDK6 inhibitors particularly in combination with mTOR inhibitors29, helped lead to multiple ongoing clinical trials for neuroendocrine and breast tumors (ClinicalTrials.gov Identifiers NCT02420691, NCT03070301, and NCT02732119). This evidence concerns the gene CDK6 and breast neoplasm.