CD8A and diffuse large B-cell lymphoma: In diffuse large B-cell lymphoma, MALDI-MSI identified resistant niches characterized by elevated AMP/ATP ratios and phosphatidylinositol accumulation (Raez et al., 2013), which guided the development of the PI3Kδ inhibitor, which normalized CD4/CD8 ratios and maximized the number of CD8+ T-stem cell memory, naive, and central memory T-cells with dose-dependent decreases in expression of the TIM-3 exhaustion marker (Funk et al., 2022).