FLG and Dry skin: The primary cause of dry skin is the deficiency of natural moisturizing factors in keratinocytes, which include key components such as amino acids (AAs), trans‐urocanic acid, pyrrolidone carboxylic acid, lactate, and filaggrin—markers of terminal differentiation of the epidermis [44, 45], as well as a decrease in hyaluronic acid (HA) in the dermis [46].