(1) The cultivation of NK cellsThe proportion of NK cells attained to 93. 1% from 4. 5% after cultured for 10 days. (2) The effects of atorvastatin on the growth of the colon cancercellsAfter cultured with atorvastatin,the inhibition rate of HCT-116 cells was higher than that in control when the density of atorvastatin increased from 5 μmol/L to 40 μmol/L after 48 h and from 1. 25 μmol/L to 40 μmol/L after 96 h ( P<0. 05 ) . Correlation analysis showed that the concentration of atorvastatin and the growth inhibition rate of HCT-116 cells were positively correlated(r[48 h]=0. 13,r[96 h]=0. 22,P<0. 05). (3) The cytotoxicity of NK cells to colon cancercells effected after atorvastatin In different atorvastatin concentrations groups,the cytotoxicity of NK cells to three colon cancercell lines was all higher than that in control ( P<0. 05 ) . The atorvastatin concentration was from 2. 5 μmol/L to 10 μmol/L for HCT-116 cells,from 5 μmol/L to 20μmol/L for SW-480 cells,and from 2. 5μmol/L to 20μmol/L for Caco-2 cells. Among the three cell lines, the cytotoxicity of NK cells to HCT116 was the highest in the same concentration. (4)NK cells by atorvastatin cutting statins 96 h,the concentration of 20 mmol/L and 40 mmol/L inhibition rate was higher than that of control group,more than other groups on NK cellgrowth without significant effect. ( 5 ) The impact of atorvastatin on MICA/B expression of colon cancercells After cultured with different concentrations of atorvastatin,the expression of MICA/B on colon cancercells was higher than that in control(P<0. 05). The concentration was 2. 5μmol/L and 5μmol/L for HCT-116 cells,10μmol/L and 20μmol/L for SW-480 cells,and from 2. 5μmol/L to 40 μmol/L for Caco-2 cells.