By examining the immunophenotype of the TME in a mouse breast cancer model, it was shown that the new selective inhibitor of phosphatidylinositol 3-kinase α (PI3Kα) CYH33 can weaken the inhibition of CD8+ T cells mediated by M2-like macrophages by reprogramming macrophages and promote the metabolism of FA in tumour tissue to enhance infiltration and activity of CD8+ T cells, exerting an anti-tumour effect [54]. The gene discussed is CD8A; the disease is breast cancer.