LIF and breast cancer: By co-culturing adipocytes with several breast cancer cell lines, the q-PCR results showed that the LIF expression of adipocytes co-cultured with human normal breast epithelial MCF-10A cells did not change compared with the control group, but the expression of LIF mRNA was significantly up-regulated in adipocytes co-cultured with breast cancer MDA-MB-231, BT549 and MCF-7 cells compared with the control group (Figure 1A).