MAPK3 and systemic lupus erythematosus: However, presumably in white female patients with lupus in summer, the decreased expression of PKC isoenzymes can lead to a state diminishing further the basically low production of interleukin (IL)-2 in T cells augmenting the existing defect in the function of activating protein-1 (AP-1) via the extracellular signal-regulated kinase (ERK)1/2 [3, 4] and other AP-1 related pathways [5, 6], or the weak effect of PKC θ in alternative splicing processes regulating gene expressions during T cell activation [7].