In a phase 1 trial of a DNA vaccine (pTVG-AR, MVI-118) in prostate cancer, persistent IFNγ immune responses were observed irrespective of GM-CSF adjuvant.1021 In a phase 2 trial of a DNA vaccine (pTVG-HP) and nivolumab in prostate cancer, among 14 patients to whom GM-CSF was added, three (21%) developed any subsequent PSA decline.1014 From this, we conclude that while GM-CSF may have provided a modest improvement for a few patients, it was not required as an adjuvant. Here, CSF2 is linked to prostate carcinoma.