Invasive lobular carcinoma of the breast (ILC) is the most common special subtype of breast cancer, and though nearly all ILC express estrogen receptor alpha (ERα), ILC represent a distinct context for ERα function among breast cancers. The cover depicts a stylized immunofluorescence image showing DNA damage foci to which Mediator of DNA Damage Checkpoint 1 (MDC1) has localized. MDC1 canonically acts in the DNA damage response. However, in their study on page 1270, Sottnik, Bordeaux, and colleagues provide evidence that MDC1 also has novel ERα co-regulator activity and is critical for ERα function in ILC cells. The authors argue that canonical functions of MDC1 in DNA repair may be superseded by novel ERα co-regulator activity in this context. Artwork by Kristine M. Sikora, PhD.