To assess the clinical relevance of the correlation between ACAA2 and SCNC phenotypes, IHC staining of ACAA2 in lung adenocarcinoma patient tumour (N = 15) was compared to ACAA2 staining in patient samples from lung carcinoid tumour (N = 12) and SCLC (N = 10), both of which exhibit NE phenotypes (Fig. 5a–d). This evidence concerns the gene ACAA2 and lung carcinoid tumor.