Once-a-day Immunosuppression(CISECON_a_day)

This is a 6-month, single-arm, multi-center, open-label, continuous cohort study. 160 subjects who had kidney transplantations at least 3 months earlier will participate in the study. All enrolled subjects will discontinue the existing Tacrolimus preparations for 6 months from enrollment and be converted to Extended Release Tacrolimus at a biologically equivalent dose. They will also discontinue enteric-coated mycophenolate sdium or mycophenolate sodium and be treated with Sirolimus and observed.