NGF and bone neoplasm: In bone cancer pain, short-term exposure of cancer-related fibroblasts, MSCs, and osteoblasts to pH 6.8 can promote the expression of inflammatory and nociceptive mediators (NGF, BDNF, IL-6, IL-8, IL-1b, and CCL5), leading to nociceptor sensitization and hyperalgesia (Di et al., 2017).