Gene expression profiling of 45 ER-regulated genes (Supplementary Table 2) in E2-stimulated tumours showed that both AZD9496 and fulvestrant significantly modulated the expression of 26 of the 45 genes tested (Fig. 2d); among these genes were AREG, PGR, CXCL12, GREB1, MYC, LITAF, and BAMBI. Of note, the two SERDs also relieved the E2 inhibitory effect on genes potentially involved in mechanisms of resistance, such as ERBB213 and TFF324. The gene discussed is GREB1; the disease is neoplasm.