LYN and systemic lupus erythematosus: Disease in Lyn+/- mice can also be accelerated to levels comparable to Lyn-/- mice by concordant loss-of-function of one allele of SHP-1 (Lyn+/−Mev+/−) or one allele of SHIP-1 (Lyn+/−SHIP-1+/−) (121), reflecting the polygenic additive model of SLE heritability.