After our initial observations through gene expression databases, namely, Oncomine and EMBL-EBI Expression Atlas, that PLXNC1 is upregulated in HCC, we generated a monoclonal antibody, clone PE4, and demonstrated its specificity for Plexin C1 in PLXNC1 knockdown and control cell clones by Western blotting and immunofluorescence. This evidence concerns the gene PLXNC1 and hepatocellular carcinoma.