NGF and Dowling-Degos disease 1: Tumor necrosis factor superfamily (TNFSF) signaling was identified as a regulated pathway in DDD, based on the significant regulation (n‐fold ± SD) of various TNFSF members in the degenerated IVD, including nerve growth factor (NGF; −8 ± 10), CD40LG (464 ± 442), CD70 (341 ± 336), TNFSF Ligand 10 (9 ± 8), and RANKL/TNFSF Ligand 11 (85 ± 74).