Across preclinical NSCLC and other tumor models, TTFields alone have shown limited impact on intratumoral CD8+ T cells, whereas protocols in which TTFields are applied alongside immune-checkpoint blockade (anti-PD-1/PD-L1 or anti-CTLA-4) consistently report immunogenic cell death, increased expression of T cell–recruiting chemokines (such as CCL2/8 and CXCL9/CXCL10), higher CD8+ TIL numbers, enhanced IFN-γ production, and improved Treg:CD8 ratios, indicating that TTFields can condition the tumor microenvironment to be more permissive for checkpoint inhibitor activity [16,17,40]. This evidence concerns the gene CTLA4 and neoplasm.