LDHA and cancer: After comparing these cell lines in vitro, we report that Notch signaling is up-regulated and associated with higher aldehyde dehydrogenase 1A1 activity aldehyde dehydrogenase (ALDH, a cancer stem cell marker) (Marcato et al., 2011), increased resistance to oxidative stress, migration, invasion, and VEGF expression, but is not essential for the proliferation of K7M2 and K12 cells, suggesting that alternative or compensatory signal transduction pathways may play a role in OS cell proliferation in this system.