If one compares the trajectory of the two ER+ breast cancers in the SEER data, the incidence of ER+PR+ breast cancers begins to increase in the mid-40s (Figure 2d, indicated by “a”), approximately 5 years before the precipitous drop in estrogen levels at 50 years and the rise in ER+PR- cancers. The gene discussed is PGR; the disease is breast carcinoma.