CD4 and neoplasm: Moreover, the abundance of CD8+, but not CD4+, T cells increased after treatment in a major fraction of patients from both arms, but these changes only reached statistical significance in the stroma for patients receiving chemotherapy alone and in tumor islets for patients receiving the combination (Fig. 2A), suggesting that chemotherapy-induced an influx of CD8+ T cells in the stroma, while adding Pembrolizumab favored their localization to the tumor islets.