Study consists of three periods with fixed sequence: 1) single dose of mycophenolate mofetil 1,000mg; 2) single dose of tacrolimus 5mg; 3) single dose of mycophenolate mofetil 1,000mg and tacrolimus 5mg. All subjects have one week of washing period between single dose administration. Blood samples are drawn up to 72 hours after drug administration. Single nucleotide polymorphisms known to result in pharmacokinetic variability of study drug are also investigated. Drug interaction is going to be assessed through the ratio of area under the concentration curve of one drug in the presence or absence of another drug.