Investigations that have focused on the depletion of FAP+ cells in the PAAD tumor microenvironment have revealed an anti-tumor effect associated with α-CTLA-4 and α-PD-L1 treatment, thereby providing further evidence in support of the immune-suppressive role of FAP+ stromal cells in the poor responsiveness to T-cell checkpoints antagonists. The gene discussed is CTLA4; the disease is neoplasm.