PCNA and cancer: Pathological picture (hematoxylin-eosin staining) of xenograft tumors from mature miR675 overexpressed group showed these tissue possessed poor-differentiation cells (1#, 2#, 4# xenograft tumors) or less moderately cancer cells (3# & 5# xenograft tumors), and pathological picture of xenograft tumor from control group showed these tissue possessed well-differentiation cells (control 1# xenograft tumor) (Figure 2Bc), and stronger Proliferating cell nuclear antigen (PCNA) positive staining in 2# miR675 xenograft tumor compared to 2# control xenograft tumor (Figure 2Bd).