To investigate the mechanism of DDIAS turnover in cells, we selected the E3 ubiquitin ligase CHIP for further study because CHIP promotes the ubiquitin ligation/chain elongation-mediated proteasomal degradation of target genes in cancer cells.12, 15, 21 First, we demonstrated that DDIAS interacted with CHIP using three reporters (URA3, lacZ and ADE2) in yeast. The gene discussed is PAICS; the disease is cancer.