LDHA and breast cancer: Thus, to determine whether ALDH-positive breast cancer cells are more radioresistant than ALDH-negative breast cancer cells, both cell populations were isolated from HBL-100 and SKBR3 via FACS (fluorescence-activated cell sorting) based on an Aldefluor assay, see Figure 1A. HBL-100 and SKBR3 cell lines were used due to their higher percentage of basal ALDH activity compared to MCF-7 cells, see Supplementary Figure S1.