PDCD1 and neoplasm: In a study of triple-negative breast cancer (TNBC), it was found that when combined with the SLC7A5 blocker JPH203 and an anti-programmed cell death 1 (PD-1) antibody, it significantly inhibited cell proliferation, invasion, and migration, increased infiltration of CD8 + T cells, and suppressed tumor immune escape [106, 107].