CD19 and cancer: CD19, BRCA1, PDGFA, CDKNA1, MMP1, and TLR4 exhibited high PPI degrees and were enriched in the PI3K-AKT signaling pathway, bladder cancer, and microRNAs in cancer; however, only high PDGFA expression levels were associated with poor OS, whereas high BRCA1 and MMP1 expression levels were associated with favorable PFS.