IL20 and major depressive disorder: Traks et al (2008) found that the frequency of the T–G–C haplotype, containing SNPs from IL-20 and IL-24 genes, is higher among patients with MDD compared with controls (Traks et al, 2008). However, Koido et al (2009) did not confirm these results in patients with a diagnosis of MDD and panic disorder. Instead, they found strong allelic and genotypic associations between both diagnoses and a polymorphism in the gene of an inhibitor of kappa light-polypeptide gene enhancer in B-cells kinase epsilon, with a stronger association with panic disorder (Koido et al, 2009).