Although clinical samples were not available to directly measure protein markers of pathway activation, such as S6 phosphorylation, analysis of the mTORC1 gene signature in RNAseq data from a phase 2 study of neoadjuvant abemaciclib (neoMONARCH, NCT02441946) revealed that abemaciclib monotherapy did indeed inhibit the mTOR pathway in HR+ breast cancer patients. Here, MTOR is linked to breast carcinoma.