Additionally, FixVAC had the ability to synergize with anti-PD-1 treatment reflected by the fact that two patients who received FixVAC after PD-1 therapy failure, underwent initial tumour regression before relapsing, to partially respond to a second round of anti-PD-1 therapy, an effect suggested to be the action of FixVAC induced PD-1+ T-memory cells that were sensitive to rechallenge with PD-1 therapy. This evidence concerns the gene PDCD1 and neoplasm.