HIF1A and systemic lupus erythematosus: In SLE, ERK1/2 kinase signalling pathway is dysfunctional with potential involvement in disease pathogenesis.19,20 Patients with SLE also display disequilibrium between Th-17 and T regulatory (Treg) cells.21 miR-21 regulates the differentiation of Th-17 cells, while HIF-1a has been proposed as an important regulator for the balance between Th17 and Treg cells.22