sentences:  In addition, they have discovered a mechanism by which schizophrenia could arise from the genetic predisposition of the human complement C4.As shown in Figure 1, four common structural variations discovered in genome-wide association studies (GWAS) studies have pointed to the high turnout of schizophrenia.Possibly, the higher levels of expression of C4 protein due to pattern of variants of the C4 gene, allows for the unwanted increase in synaptic pruning (an effect produced by the effector proteins of the complement system in which the C4 partakes).