Zattarin et al., described in a conference abstract that PLR at baseline and also after the first three treatment cycles related to worse PFS in 308 HR + /HER2- advanced BC patients receiving CDK4/6i42 while Weiner et al., presented in a meeting abstract a significant association between PLR at baseline and PFS using univariate und multivariate analysis in a more stringent cohort of 89 1L CDK4/6i treated CDK4/6 patients44. This evidence concerns the gene CDK4 and breast cancer.