PRKAA2 and breast cancer: To examine the effect of SESN2 modulation on AMPK expression and activity, we first identified the most prominent AMPK heterotrimeric complex in MCF7 breast cancer cells by performing serial immunoprecipitations with antibodies against each AMPK subunit (α1–2, β1–2, and γ1–3), followed by immunoblotting (Figure 1A).