Since MDA-MB-231 cells are estrogen receptor negative [41], we compared the expression of PPARγ and hTERT genes in estrogen receptor-negative (N = 69) and estrogen receptor-positive (N = 225) tumor samples and no correlation was observed between the two genes in either estrogen receptor-positive (r = -0.156) (Figure 6B) or estrogen receptor-negative (r = -0.08) (Figure 6C) tumors. The gene discussed is ESR1; the disease is neoplasm.