IL6 and squamous cell carcinoma: Multivariable analysis revealed that squamous cell carcinoma histology (OR = 4.471, 95% CI = 1.037-21.699; P = 0.045) and baseline IL-6 levels ≤5.4 pg/mL (OR = 4.494, 95% CI = 1.089-18.541; P = 0.038) were independently associated with higher odds of achieving an objective response.