Inclusion Criteria:  New diagnosis with proliferative LN based on kidney biopsy done within 4 weeks of enrollment Diagnosis with childhood-onset SLE (cSLE) as per the ACR criteria95, 96 Age 8 - 17 years at the time of enrollment96 Tolerates oral MMF  Exclusion Criteria:  Perceived or stated inability to adhere to study protocol, Lack of use of highly effective birth control method. Presence of cSLE features that a-priori suggest that the patient benefits from other therapy than that suggested by the study protocol, History of significant kidney disease prior to the diagnosis with cSLE, Need for renal replacement therapy at the time of enrolment, Concurrent therapy with CYC or rituximab.