Importantly also in this context, none of the reported independent associations between RBP4 concentrations and other recorded characteristics in the present study were altered upon further adjustment for alanine and aspartate aminotransferase concentrations. Aminotransferase levels were previously shown to independently relate to metabolic risk and atherosclerosis in RA. We assessed the production of 4 endothelial activation molecules that mediate the initial stages of atherosclerosis. Endothelial activation is strongly up-regulated and associated with prevalent and incident atherosclerosis in RA. We comprehensively adjusted for a wide range of confounders including the anthropometric measure of waist-hip circumference that is associated with RBP4 concentrations and cardiovascular events in non-RA subjects. Anthropometric measures are also related to atherosclerosis in RA. This study has however additional limitations. Retinol and iron status are further potential confounders in the present context and were not evaluated. Micronutrient deficiencies exist in urbanized South Africans from which our participants originated. In a recent national survey on 3229 adult South Africans, retinol intake was documented to be adequate and iron intake inadequate. Also, the effects of RBP4 on endothelial activation occur independently of retinol. As was done in the original study by Graham and colleagues as well as in many other reported investigations that followed, RBP4 concentrations were measured by ELISA, which can undervalue RBP4 concentrations in insulin resistant persons. Quantitative western blotting standardized to full-length RBP4 protein is suggested to be the most reliable method to measure RBP4 levels. Nevertheless, in an investigation by von Eynatten and colleagues, RBP4 concentrations quantified by ELISA were strongly associated with those measured by western blotting. Finally, circulating RBP4 concentrations do not necessarily represent its tissue concentrations. The Fanconi anemia group C protein is a multifunctional protein, with roles in several cellular processes, such as DNA damage signaling, redox regulation, transcriptional regulation, and apoptosis. Mutations in the FANCC gene lead to Fanconi anemia, a genetic disease characterized by a progressive depletion of bone marrow cells. This disease is also associated with MK-0683 various congenital malformations and an increased risk of malignancies. There are 16 FA disease-associated genes that form an entity known as the FA pathway that enacts a global response to DNA crosslink damage. FANCC is the cytoplasmic component of the FA pathway, and in association with the Fanconi anemia group E protein, translocates to the nucleus in response to crosslink damage. Nuclear FANCC associates with other components of the FA pathway to compose the FA core complex. Besides this association with FA core complex proteins, FANCC binds several proteins involved in various cellular functions, such as oxygen radical metabolism, signal transduction, transcription, and apoptosis.