CD4 and neuroblastoma: Furthermore, animals cured by anti-CTLA4 therapy from idMMR tumors had an increase in tumor-reactive T cells (CD39+CD8+ and CD39+CD4+ T cells) and activated CD4+ T cells (CD38+CD4+ T cells) with higher cytotoxic potential (CD107a+CD4+ T cells) in their spleens after rechallenging with the pMMR neuroblastoma tumors.