Notably, steroid hormone (e.g., cortisol) and neuropeptide Y (NPY) have emerged as potential biomarkers for monitoring stress‐related disorders (e.g., cardiovascular dysfunction) and mental health conditions (e.g., chronic stress and depression).[174] Recent research has demonstrated a significant correlation between the concentrations of these hormones in sweat and blood, despite their markedly lower levels in sweat compared to serum. The gene discussed is NPY; the disease is major depressive disorder.