CSF2 and cancer: Sipuleucel-T, the only approved immunotherapy for PC, is a therapeutic cancer vaccine composed of autologous antigen-presenting cells (APCs) extracted via leukapheresis that is activated ex vivo with a fusion protein (PA2024), which contains antigen prostatic acid phosphatase (PAP) and granulocyte-macrophage colony-stimulating factor (GM-CSF), a cytokine that stimulates APC maturation.