The autocrine function we ascribe to IL-6: (i) is consistent with the fact that high expression of IL-6 receptor in spindle-shaped stromal cells associates with shorter disease-free survival, metastasis-free survival, and overall survival in breast cancers [28]; (ii) is consistent with a role of IL-6 in maintaining CAF activation [29]; (iii) evokes the reported role of autocrine, CAFs derived IL-6 in endocrine resistance [11, 30]. Here, IL6 is linked to breast cancer.