Several studies have since shown that chemical exposure and AhR activation affect processes of mammary gland differentiation, disrupting pregnancy-related differentiation and milk production, and increasing the risk of breast cancer (Warner et al., 2002; Vorderstrasse et al., 2004; Lew et al., 2011; Belton et al., 2018; Kay et al., 2022). The gene discussed is AHR; the disease is breast cancer.