Levels of ATF-4 mRNA between normoxia and anoxia do not vary. (A) MDA-MB 435 cells were incubated for 16 hours in either normoxia or anoxia, and ATF-4 mRNA levels were analyzed using RPA. As indicated, abundant ATF-4 mRNA was present in similar levels under normoxia and anoxia. (B) Immunoblot control for the RPA demonstrated strong anoxic induction of the ATF-4 protein. n indicates normoxia; A, anoxia; LC, loading control (small nuclear U6 RNA).