PALB2 and large cell neuroendocrine carcinoma: These drugs target homologous recombination repair deficient tumors by inhibiting PARP, a key enzyme in single-stranded DNA break repair, leading to tumor cell death.29, , –32PALB2 mutations have been reported in 2.5% of patients with MSI-H colorectal cancer; however, to the best of our knowledge, PALB2 mutations have not been documented in large-cell neuroendocrine carcinoma.33