 As is well known, immunosuppressive treatment IS after liver transplantation has several and frequents adverse effects that limit the survival of the graft and recipients. Because of that, it is desirable that these recipients were able to receive a mild IS regime with a better safety profile. An attempt to get that aim has been evaluated in several trials in the past, and consist in to change the IS regime from an calcineurin inhibitors CNI based to another less intense and with less adverse effects based on mycophenolate mofetil MMF, which is known to have a better safety profile. The success rate of this strategyi.e. complete conversion in absence of rejection has a wide range from 100 to 50 approximately. However it is accepted that this strategy is associated with the improvement of several adverse effects of CNIs such as renal failure and dyslipemia. This studys aim is to perform IS conversion from CNI to MMF monotherapy and look for transcriptional biomarkers employing a whole genome expression study performed with microarrays at baseline on liver tissue andor PBMCs to try to find a differential gene expression able to correlate with a successful conversion and thus, to generate a set of transcriptional biomarkers potentially able to predict the result of the IS conversion on an independent cohort of liver recipients. 