HK2 and neoplasm: Moreover, IHC revealed that the xenografted tumor tissues formed by SiHa-HK2 and HeLa-HK2 exhibited much stronger Ki67 (a cell proliferation marker) and HK2 stains than those formed by their control cells (SiHa-GFP and HeLa-GFP, Figure 3M, Supplementary Figures S1A, C).