IL6 and nutritional deficiency disease: Chronic inflammation exacerbates muscle catabolism and appetite suppression through pro-inflammatory cytokines such as IL-6 and TNF-α, leading to nutritional deterioration; in turn, malnutrition further impairs immune function and suppresses the production of anti-inflammatory factors, creating a positive feedback loop where “inflammation-driven nutrient depletion exacerbates nutritional deficits, which in turn intensify inflammation.” This vicious cycle synergistically accelerates cancer-related mortality (39).