Our finding of the increased expression of PDYN contributes to the findings of Taneda et al. [52], who in 2011 demonstrated a decrease in dynorphin A and κ-opioid receptor levels in the epidermis of pruritic psoriasis patients, as this overexpression may be an attempt to compensate for the decrease in dynorphin A. Unfortunately, our attempt to analyze the expression of κ-opioid receptor gene OPRK1 was not successful as the mRNA level did not reach the detection threshold. The gene discussed is PDYN; the disease is psoriasis.