Who bit Beyonce?

We don’t know. Kinda like we don’t know what to do with estrogen receptor (ER)-positive breast cancer that doesn’t respond to neoadjuvant endocrine therapy. A new study shows ER+ tumor cells resistant to letrozole have activated E2F gene expression, which is suppressed both in vitro and in vivo by CDK4/6 inhibition, paving the way for an adaptive treatment paradigm that takes a bite out of initially non-responding ER+ breast cancers. | Guererro-Zotano, Clin Cancer Res 2018