In another phase 1 and 2a clinical trial, lupus patients who received Ld-IL2 therapy also showed improved disease activity evaluated by the Safety of Estrogens in Lupus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) and increased frequency of CD25+Foxp3+ TREG cells [37]. Here, FOXP3 is linked to systemic lupus erythematosus.