NGF and neuroblastoma: The MAPK/ERK pathway is reportedly activated by ectopic NGF secretion in neuroblastoma, breast cancer, colon cancer and pancreatic ductal adenocarcinoma (PDAC) (Romon et al. 2010; Han et al. 2022; Xin et al. 2016; Lei et al. 2022; Lebedev et al. 2021).