SIRT1 and breast carcinoma: In addition, we classified breast cancer patients into four groups according to the combined expression status of SIRT1 and N1IC as follows: SIRT1-high/N1IC-low (n = 34); SIRT1-low/N1IC-low (n = 5); SIRT1-high/N1IC-high (n = 81); and SIRT1-low/N1IC-high (n = 30).