Previous investigations, including genome-wide association studies, mainly focused on discrimination between favorable and unfavorable gene variants and rarely considered heterozygosity as the status with potentially specific phenotypic consequences. The data presented above look intriguing and certainly deserve validation in independent case-control series. If the significance of the CASP5 Ala90Thr heterozygosity is confirmed, functional properties of the CASP5 allelic variants need to be evaluated in laboratory assays. Furthermore, the role of CASP5 polymorphism in predisposition to autoimmune and inflammatory diseases has to be considered. 

The study also included a table showing the distribution of CASP5 Ala90Thr heterozygous genotypes according to gender and smoking status. The number of subjects, observed minor allele, expected number of genotypes, frequency of heterozygotes, and p-value for deviation from Hardy-Weinberg equilibrium were recorded for each group.

Lastly, the study was supported by the Russian Foundation for Basic Research (grants 07-04-91000, 07-04-00122, and 08-04-90105). Several references were cited throughout the text.