Considering that NUMB-PTBL isoforms (i.e., NUMB1 and NUMB2) were located on the plasma membrane of cells grown at HCD, while the NUMB-PTBS isoforms (i.e., NUMB3 and NUMB4) were persistently distributed in the cytoplasm (Figure 2B), we sought to determine the relative expression levels of NUMB-PTBL and NUMB-PTBS in healthy human liver versus HCC tissues. Here, NUMB is linked to hepatocellular carcinoma.