ALDH1A1 and breast cancer: Correlating those cells with breast cancer risk factors specifically in premenopausal women showed that having a low number of ALDH1+ CD44+ CD24– r/o cells in the stroma of TDLUs was associated with family history of breast cancer, and having a low number of ALDH1+ CD44– CD24– s/p cells was associated with the breast cancer risk factor nulliparity [20].