STAT3 and breast cancer: A cocktail of CAF/MSC-secreted factors induced the expression of a number of cancer-related proteins, such as integrin β1, P-AKT, P-STAT3 (signal transducer and activator of transcription 3), CAIX (carbon anhydrase IX), IGF1R (insulin-like growth factor 1 receptor) and Bcl-3 (B-cell leukemia/lymphoma 3), in breast cancer cells.