CD4+CD25-FOXP3+CD45RA+Tregs were expanded in the presence of cancer ASCs butCD4+CD25+Foxp3+CD45RA+regulatory T cells were up-regulated in the presence of both cancer- and normal-ASCs.This up-regulation was statistically significant in breast cancer-ASCs compared to the cells cultured without ASCs(P=0.002). Here, CD4 is linked to cancer.