PRKAA1 and melanoma: Hence, to determine whether AMPKα1/α2–deficient Treg cells are functionally impaired in the TME, we challenged Prkaa1/2fl/flFoxp3YFP–Cre and control mice with B16 melanoma tumors, finding that Prkaa1/2fl/flFoxp3YFP–Cre mice experienced lower tumor volume over time and lower tumor weights at day 15 after engraftment (Figure 2, A and B).