Concerning particular types of breast cancer subtypes, the increases found with exposures to i.e., organic solvent, PAHs, and synthetic fibers among ER-positive/PR-positive tumors support the idea that certain occupational chemicals present in the workplace, acting as endocrine disruptors, in particular xenoestrogens, can favor the onset of hormone receptor-positive breast cancers [29]. The gene discussed is ESR1; the disease is breast carcinoma.