CYP4Z1 and neoplasm: Additionally, we performed an in vivo tumorigenic assay with MDA-MB-231 cells after CYP4Z1- or CYP4Z2P-3′UTR knockdown and showed that the knockdown of CYP4Z1- or CYP4Z2P-3′UTR remarkably reduced the tumor-initiating potential of MDA-MB-231 cells (Fig. 2g–k).