DLL3 and neuroendocrine carcinoma: Although a potential limitation related to differences in capturing intratumoral heterogeneity, excellent concordance between slides and TMA blocks has been demonstrated for evaluation of DLL3 IHC positivity in previous similar studies.31 In the advanced GEP NEC cohort, three of 46 patients with DLL3 IHC-positive disease received DLL3-targeted therapies in the later-line setting, possibly affecting OS analyses.