ALDH1A1 and large cell neuroendocrine carcinoma: In addition, Morise et al. [101] found that LCNEC patients positive for aldehyde dehydrogenase 1 (ALDH1) in IHC had significantly worse recurrence-free survival (RFS) and OS rates than those with ALDH1 negative (5-year RFS: 39% vs. 67%, p = 0.009; 5-year OS: 50% vs. 79%, p = 0.021).