Only one transcript for KLK10 was identified by RT-PCR in lung tissue, whereas KLK11 expressed at least four alternative transcripts. Quantitative analysis of KLK10 and KLK11 expression levels was assessed by real-time PCR, in a cohort of 47 patients with non-small-cell lung cancer (NSCLC). Expression levels of these genes were widely distributed in the population studied. Multivariate analysis revealed a correlation between KLK10 over-expression and the squamous cell carcinoma histotype (p=0.034). There was no correlation between gene expression and patient survival. Overall, both genes behaved similarly (p<0.001). These results suggest a co-regulation of KLK10 and KLK11 expression in lung and a lack of KLK10 suppressor role in NSCLC. Finally, our findings indicate that these genes are likely involved in normal physiology processes in bronchus.