CCL19 and neoplasm: The results showed that although its loading in tumor decreased on the 21st day compared to it on the 11th day, rPR8-CCL19 was mainly concentrated in tumor and was almost undetectable in other tissues; while wtPR8 wildly distributed in various tissues on the 11th day, it was largely undetectable in all tissues on the 21st day (Figure 4H).