More recent data have shown that an engineered ubiquitin ligase PTBU-box can promote the ubiquitination and degradation of IGF-IR and IR, and thus effectively inhibit in vitro and in vivo tumorigenesis of liver cancer HepG2 and cervical cancer HeLa cells that over-express IGF-IR and IR (39). The gene discussed is IGF1R; the disease is cervical cancer.