Comparison of gene-expression between plastic and mammosphere cultures also suggests that VDR mRNA was significantly down-regulated in mammospheres isolated from breast cancer cells (MCF7∶56.2±4.6%; SKBR3∶59.5±6.2%; and HRas: 72.4±3.5%) compared to cells grown on plastic; however, there was no significant difference in VDR expression between mammospheres and plastic cultured cells isolated from mammary epithelial HMLE (Figure 2C). The gene discussed is VDR; the disease is breast cancer.