KL and cancer: Cancer survivors exhibited significantly lower Klotho levels than non-cancer participants (813.74 ± 8.55 vs. 849.69 ± 5.08 pg/mL; P < 0.0001), as well as higher PIV values (320.07 ± 6.58 vs. 299.07 ± 3.44; P = 0.0059).