Being underweight has been used as an indicator of undernutrition due to a short term nutritional deficiency.8 However, anin vitro study using peripheral blood mononuclear cells (PBMC) taken from children suffering from protein energy malnutrition (PEM) contradicted this study, which showed an increment in IL-6 expression after stimulation with LPS,70 even though it was expressed earlier, reached its peak earlier, and lasted longer than controls in rats.71 As the immune function is costly in terms of energy, it has negative effects on growth. Here, IL6 is linked to nutritional deficiency disease.