TK1 and invasive carcinoma: The ratio between the TK1 expression in the cytoplasmic and nuclear group and the total TK1 group increased from CIN grade I to grade III (I = 0.42, II= 0.61, III= 0.67), but did not increase further in the invasive carcinoma pathological stages II and III (II = 0.63, III = 0.66).