Among these gene variants, the glucokinase regulatory protein has been further confirmed as linked with steatosis in children, in obese patients, and in populations of different ethnicity. GCKR seems to interfere with glucose and lipid homeostasis by regulating glucose storage/disposal and by LY2109761 providing substrates for de novo lipogenesis via inhibition of glucokinase, but its potential association with the severity of liver damage has never been tested Having this in mind, the main outcome of this study was to assess whether GCKR rs780094 was associated with the histological features of liver damage in patients with biopsy-proven NAFLD, after correction for PNPLA3 genotype. In our study we also demonstrated that patient homozygous for the T allele of GCKR had higher serum triglycerides levels, in agreement with previous finding by Speliotes et al, and with the hypothesis that the GCKR rs780094 SNP could lead to a higher activity of liver glcokinase. In addition we also observed higher triglycerides levels in Sicilian compared with Center/ Northern Italy cohort, probably attributable to the more unhealthy lifestyle characterizing the southern population. By contrast we did not identify any association between severity of steatosis and GCKR genotype. Our data are not in contrast with the study of Speliotes et al and more recent studies showing a link between GCKR SNP and the presence of steatosis. We did not test subjects without steatosis of the same geographic area, and therefore we were not able to discriminate between presence/absence of fatty liver infiltration. Obviously, the lack of these data could partially affect the interpretation of our results, and in particular of the significance of the real effect of GCKR SNP on steatosis. Finally, we did not confirm the reported association between PNPLA3 genotype and severity of liver fibrosis. Differences in the characteristics of the individual study cohorts could explain the lack of association in our cohort. The main limitation of this study lies in its cross-sectional nature, making it impossible to dissect the temporal relation between genetic background and progression of liver disease over time. This issue should be tested in longitudinal analyses. A further methodological question is the potentially limited external validity of the results for different populations and settings. Our study included cohorts of Italian patients enrolled at tertiary care centers, who may be different, in terms of both metabolic features and severity of liver disease, from the majority of prevalent cases of NAFLD in the general population. Quantitative real-time reverse transcription polymerase chain reaction is one of the most effective and sensitive techniques for gene expression analysis. However, enabling comparisons across different samples, qRT-PCR data must be normalized to correct variations in pipetting, RNA concentration, reverse-transcription, and efficiency of PCR amplification.