Immunofluorescence analysis showed that ERBB2 was clearly expressed in the cytoplasm and cell membrane of human epidermal squamous cell carcinoma A-431 cells, human osteosarcoma U2OS cells, and human glioma U251-MG cells, indicating that ERBB2 expression was not limited to specific cell lines (Figure 4D). Here, ERBB2 is linked to glioma.