CRP and melanoma: Several limitations should be acknowledged: (1) both NHANES and the institutional cohort relied on cross-sectional or retrospective designs, which preclude causal inference; (2) important covariates—including tumor stage, histologic subtype, ultraviolet exposure, genetic mutations, and C-reactive protein—were unavailable; (3) statistical power was limited by the relatively small number of melanoma cases (249 in NHANES and 101 in the institutional cohort); and (4) self-reported BMI and smoking status may have introduced recall and social-desirability biases.