FOXP1 deficiency is associated with poorer prognosis in breast cancer and promotes the development of lung carcinoma,[40] whereas FOXP1 can serve as an oncogene leading to poor outcomes in large B‐cell lymphoma.[41] Moreover, FOXP1 inhibits T follicular helper cell differentiation[42] and is also essential for the optimal expression of FOXP3 during the onset of iTreg induction.[43] This study revealed that FOXP1 is a key target of NAT10‐mediated ac4C modification in CCa and first elucidated its underlying functions and mechanisms in metabolic reprogramming and immunosuppression. Here, FOXP1 is linked to breast carcinoma.