PDCD1 and hyperinsulinemic hypoglycemia, familial, 4: A significant advancement in precision oncology was the tissue-agnostic FDA approval of the programmed cell death-1 (PD-1) inhibitor pembrolizumab for the treatment of any tumor with mismatch repair deficiency (MMRd) or high microsatellite instability (MSI-H), regardless of the tissue of origin [11].