The serine/threonine kinase MAP4K3 (also named GLK) directly interacts with and phosphorylates PKCθ in T cells, resulting in T-cell activation.13 GLK overexpression in murine T cells induces IL-17A production and T-cell hyperactivation, leading to autoimmune inflammatory diseases.14 Moreover, GLK is overexpressed in T cells in patients with autoimmune diseases including SLE13 15–18; GLK-overexpressing T-cell population is correlated with the disease severity of patients with SLE.13 17 To date, the mechanism of GLK overexpression in patients with SLE remains unclear. The gene discussed is MAP4K3; the disease is systemic lupus erythematosus.