KLK3 and neoplasm: Findings from the Kruskal–Wallis H test (Table 3) further indicated that higher Gleason scores (preoperative: χ2 = 24.2127, p = 4.77 × 10−4; postoperative: χ2 = 24.7385, p = 1.57 × 10−4) and advanced tumor stage (χ2 = 45.1013, p = 3.79 × 10−9) were each associated with elevated PSA levels, reflecting more aggressive disease.