KLK3 and obesity due to melanocortin 4 receptor deficiency: However, it remains unclear how the convergence of these pathways drives obesity-linked cancer.[10] Although the advent of prostate specific antigen (PSA) testing has resulted in earlier prostate cancer detection, its significance in lowering prostate cancer-specific mortality is significantly less certain.[11] The impact of potential modifiers of PSA levels, with particular attention focused on obesity, may be represented in the contradictory findings of screening trials.