These findings align with those reported in an analysis of 1303 tumor samples from patients with HR+/HER2− disease across the MONALEESA-2, MONALEESA-3, and MONALEESA-7 trials, which demonstrated that the cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor ribociclib plus endocrine therapy benefited patients with tumors characterized by all molecular subtypes except BL19. This evidence concerns the gene CDK4 and neoplasm.