IL6 and vitamin D deficiency: In a study of the use of corticosteroid (CTC) therapy to prevent TB-IRIS, we found that while CTC use decreased CXCL10, IFNγ, IL-6, IL-8, IL-10, IL-12p40, IL-18, and TNF prior to ART initiation, it did not prevent IRIS onset, although it did decrease severity, and that severe vitamin D deficiency (total 25(OH)D < 25 nmol/L) was associated with higher baseline IL-6, IL-8, and TNF, irrespective of IRIS status [125].