ZKSCAN4 and schizophrenia: Additionally, our earlier two-stage GWAS also found that three single-nucleotide polymorphisms (SNPs; i.e., rs1233710 in ZKSCAN4, rs1635 in NKAPL, and rs2142731 in PGBD1) within this locus had a strong association with schizophrenia in a Chinese Han population [22].