... LA, Yu CY: Gene copy-number variation and associated polymorphisms of complement component C4 in humansystemic lupus erythematosus (SLE): low copy number is a risk factor for and high copy number ... SQ,Zhu CY, Xu Q, Gao JP, Hu WL, Ni C, Pan TM, Yao S, He CF, Liu YS, Yu ZY,Yin XY, Zhang FY, Yang S, Zhou Y, Zhang XJ: Genome-wide associationstudy for vitiligo identifies susceptibility loci ... njury [15]. Unfortu-nately, the mechanisms by which C4 abnormality contri-butes to the protection of organ-specific autoimmunity arepoorly understood. Nevertheless, whether a potentialgene-gene...