STAT3 and breast carcinoma: In several cancers such as prostate, non‐small‐cell lung cancers, cervical cancers, renal cell carcinoma, and glioblastoma, activation of STAT3 or STAT5 is associated with a worse prognosis; conversely, STAT3 is associated with favorable prognosis in breast cancer and in some studies in colorectal cancer and head and neck squamous cell carcinoma (Thomas et al., 2015).