GPR68-ATF4 signaling is a novel prosurvival pathway in glioblastoma activated by acidic extracellular microenvironment oleh Charles H. Williams, Leif R. Neitzel, Jessica Cornell, Samantha Rea, Ian Mills, Maya S. Silver, Jovanni D. Ahmad, Konstantin G. Birukov, Anna Birukova, Henry Brem, Betty Tyler, Eli E. Bar, Charles C. Hong