ERBB2 and breast cancer: Ribociclib significantly increased PFS vs placebo in patients who had received prior (neo)adjuvant chemotherapy (HR = 0.548; 95% CI 0.384–0.780) or ET (HR = 0.538; 95% CI 0.384–0.754) and in patients without prior (neo)adjuvant chemotherapy (HR = 0.548; 95% CI 0.373–0.806) or ET (HR = 0.570; 95% CI 0.380–0.854) (Conte P et al. First-line ribociclib + letrozole in patients with HR+/HER2– advanced breast cancer who received prior (neo)adjuvant therapy: a subgroup analysis of the MONALEESA-2 trial.