The importance of genetic variability was further illustrated by Docea et al. (3), who highlighted that polymorphisms in several CYP450 genes (CYP1A1, CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A4) could modulate susceptibility to neurotoxicity, endocrine disruption, immune dysfunction, and reproductive impairments following xenobiotic exposure. The gene discussed is CYP2C9; the disease is immune system disorder.