GALC and breast cancer: Furthermore, the ratio of Galc-positive cells showed that 1 nmol/l ATRA (11.33%), 10 nmol/l ATRA (27.17%) and 100 nmol/l ATRA (47.17%) significantly promoted differentiation in U87 SLCs compared with that of BC group (5.67%; P=0.026, P<0.001 and P<0.001, respectively).