Table 3: The cytotoxicity of NK cells to MKN45 cells and VIP effect on it.

Groupn OD490

A: MKN45 + NK + VIP (1 × 10−5)12
B: MKN45 + NK + VIP (1 × 10−6)12
C: MKN45 + NK + VIP (1 × 10−7)12
D: MKN45 + VIP (1 × 10−5)12
E: MKN45 + VIP (1 × 10−6)12
F: MKN45 + VIP (1 × 10−7)12
G: MKN45 + NK12
H: MKN45 (blank control)12

, . a stands for compared with group H. b stands for compared with group G. c stands for compared with group A.