For example, the shares of the genera Alkanindiges (P=0.012), Micrococcus (P=0.019), Caulobacter (P=0.011), Proteus, Brevibacillus, Kocuria (P=0.019), and Parasediminibacterium are greater in estrogen receptor-negative (ER-) than in estrogen receptor-positive (ER+) breast cancers (31). The gene discussed is ESR1; the disease is breast cancer.