SPHK1 and lung adenocarcinoma: Incubation of A549 with the SK1 inhibitors DMS and fingolimod induced additional downregulation of SK1 in resveratrol-treated lung adenocarcinoma cells, implying that the combined use of anti-proliferative effectors with naturally occurring anti-tumor agents could turn out to be a useful tool for reducing the pro-survival potential of cancer cells.