Methods① 3-[4,5-Dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and plate clone formation assays were performed to confirm the in vitro anti-tumor activity of Caerin 1.1 and Caerin 1.9. ② Chloramine-T was used to label Caerin 1.1 and Caerin 1.9 with 131I, and the Cell Counting Kit 8 assay was performed to analyze the inhibitory effect of unlabeled Caerin 1.1, unlabeled Caerin 1.9, 131I-labeled Caerin 1.1, and 131I-labeled Caerin 1.9 on the proliferation of NSCLC cells. An A549 NSCLC nude mouse model was established to investigate the in vivo anti-tumor activity of unlabeled Caerin 1.1, unlabeled Caerin 1.9, 131I-labeled Caerin 1.1, and 131I-labeled Caerin 1.9.