The expression levels of CD19 was further assessed in the four immune subtypes of pancreatic cancer samples and normal samples, and was found (Figure 8G) to be upregulated in pancreatic cancer samples of IS1 immune subtype, IS2 immune subtype, and IS3 immune subtype compared with normal samples, while there was no significant difference in the expression between pancreatic cancer samples of IS4 immune subtype and normal samples. Here, CD19 is linked to familial pancreatic carcinoma.