TNFSF8/TNFSF15 and TNFSF13 loci are also associated with the risk of IgA nephropathy, while TNFSF4/TNFSF18 locus has previously been associated with the risk of eczema, asthma and narcolepsy, all with concordant effects to IgA levels (Fig. 2c and Supplemental Table 5). This evidence concerns the gene TNFSF13 and narcolepsy.