PCNA and cancer: Pathological picture (hematoxylin-eosin staining) of three xenograft tumors from mature miR675 overexpressed group showed these tissue possessed poor-differentiation cells (5# & 6# xenograft tumors) or less moderately cancer cells (4# xenograft tumors) (Figure 2Ac), and stronger Proliferating cell nuclear antigen (PCNA) positive staining in 6# xenograft (Figure 2Ad).