2.2. Establishment of Lewis lung cancer mouse model and in vivo immunization

Twenty BALB/C mice (18–20 g) were randomly selected, and 0.2 ml (2 × 10⁶ cells) of LLC1 cells was injected into the right side of each mouse. Mice were immunized 3 days later. The specific method is as follows: 20 mice were classified into four groups (n = 5): PBS control group (400 μl PBS), low‐dose group (10 μg silkworm peptide), medium‐dose group (20 μg silkworm peptide), and high‐dose group (50 μg silkworm peptide).

PBS and silkworm peptide were subcutaneously injected at the back of the neck and bilateral inguinal injection. The second immunization was performed in the same manner at 7 days after the first immunization. Mice were received immunization for twice.