Cyclosporine and tacrolimus are calcineurin inhibitors that are commonly used as immunosuppressive agents in solid organ transplantation. CNIs are recommended as first-line therapy for children with steroid-resistant NS and as steroid-sparing agents for children with frequently relapsing or steroid-dependent NS .Calcineurin inhibitors (CNIs) inhibit T-cell activation and may be exerting their effect in nephrotic syndrome through this mechanism.