Similarly, for patients with cancer-related pain, the PEG score was not significantly associated with circulating cytokine levels for IL-1β (β = −0.014, 95% CI = −0.070–0.042, p = 0.627), IL-1α (β = −0.020, 95% CI = −0.074–0.033, p = 0.452), TNF-α (β = 0.008, 95% CI = −0.008–0.023, p = 0.319), IFN-γ (β = −0.029, 95% CI = −0.074–0.017, p = 0.212), IL-2 (β = −0.021, 95% CI = −0.060–0.019, p = 0.300), or IL-10 (β = 0.025, 95% CI = −0.016–0.066, p = 0.222). This evidence concerns the gene IL2 and cancer.