MKI67 and neoplasm: Moreover, comparisons of the tumor xenografts by immunohistochemistry showed that the stimulatory effects of KCTD12 on tumor growth were attributable to increases in cell proliferation, a finding supported by our observation of a higher Ki-67 proliferation index (the mean index increased from 39.5±7.9% in the vector control group to 70.7±6.6% in the wild-type KCTD12 group; P<0.01; Figure 6e).