BRCA1 and ovarian cancer: Based on these considerations, the low levels of BRCA1 appeared to be mediated by promoter hypermethylation, making this an appropriate model to investigate the physiological relationship between BRCA1 and AGTR1. Notably, the expression levels of AGTR1 were decreased markedly (Figure 3Biii), along with hypermethylated promoter-mediated BRCA1 deficiency in ovarian cancer (Figure 3Bii).