GPR19 and small cell lung carcinoma: These differences in GPR19 expression between the different lung tumour entities were statistically significant (Kruskal–Wallis test, p < 0.001; pairwise Mann–Whitney tests, SQC vs. ADC/TC/AC/SCLC, p < 0.001; SQC vs. LCNEC, p = 0.005; ADC vs. SCLC, p = 0.025; LCNEC vs. TC, p = 0.008; LCNEC vs. AC, p = 0.010; LCNEC vs. SCLC, p = 0.007).