TFRC and cancer: In addition, miR-221 exerts oncogenic & miR-222 exerts both oncogenic & tumor suppressor roles and are also commonly upregulated by HBx and by targeting CXCL4/12 and transferrin receptor protein 1 (TFRC) respectively, and play key roles in facilitating cell cycle advancement while suppressing apoptosis, thus supporting cancer cell growth (18, 19).