ROBO3 and obesity due to melanocortin 4 receptor deficiency: Although the NELL2-Robo3 complex is involved in the activation of axonal guidance [27], NELL2 is also involved in various cancers, for instance, the NELL2/cdc42-BAF complex in Ewing’s sarcoma cells [28], fat mass and obesity-associated protein (FTO)/E2F1/NELL2 in non-small-cell lung cancer (NSCLC) [29], and NELL2/N-cadherin in embryonic carcinoma cells [30].