IL17A and obesity due to melanocortin 4 receptor deficiency: In SpA, a recent study with secukinumab (an interleukin 17A inhibitor) in patients with ax-SpA and PsA patients using the same methodology (n = 138 patients and maximum follow-up period of 5 years) identified month 12 as the timepoint the curve changed from fast to slow decay, and diagnosis, obesity, and gender as relevant variables: the best retention rates were seen in the groups of women with ax-SpA and men with PsA (13).