FOXP3 and neoplasm: To address the specific role of AMPK in tumor-associated Tregs, we crossed mice carrying loxP-flanked Prkaa1 alleles (AMPKfl/fl) with Foxp3YFP-Cre (referred to as Foxp3-Cre) mice [24] to generate progeny in which AMPK alleles are conditionally deleted in Treg cells, but not in other T cells (hereafter referred to as AMPKfl/flFoxp3-Cre mice; AMPK+/+Foxp3-Cre mice were used as control (WT)).