NGFR and neuroblastoma: VPA (1 mM) and entinostat (1 μM) had either no effect or slightly increased p75NTR expression in non-neuroblastoma human cell lines, including human dermal fibroblasts (HDF), human embryonic kidney 293 cells (HEK 293), human prostate carcinoma PC-3 cells, and human cervical carcinoma HeLa cells (Supplementary Figure S1).