MKI67 and hepatocellular carcinoma: In HCC, the number of Ki67+ cells was higher than in NTL at all ZTs (ZT02, 14, 20, p < 0.0001; ZT08, p < 0.01), but in contrast to the NTL, the number of Ki67+ cells showed two peaks, one during the early light phase (ZT02, p < 0.05) and the second in the late dark phase (ZT20, p < 0.01) as compared with the trough at ZT08 (Figure 1D).