The tumor cell‐derived matrix of lobular breast cancer: a new vulnerability

Invasive lobular carcinoma (ILC) of the breast is a very common disease. Despite its prevalence, these tumors are relatively understudied. One reason for this is a relative lack of models for ILC. This challenge was addressed by Brisken and colleagues through development of an intraductal injection‐based xenograft system for the study of ERα + breast cancers, including both ILC and more common invasive ductal carcinoma (IDC; Sflomos et al , 2016). In this issue of EMBO Molecular Medicine, the same group have applied intraductal injection‐based xenografts to identify novel tumor cell‐specific transcriptional signatures in ILC (Sflomos et al , 2021). In doing so they found overexpression of lysyl oxidase‐like 1 (LOXL1) to be both responsible for the frequently seen stiff collagen‐rich extracellular matrix of lobular breast cancer and essential for their robust growth and metastatic dissemination in vivo , thereby identifying a novel therapeutic target.