P4HA1 and neoplasm: Similarly, oeP4HA1 group immunofluorescence in U251 GSCdECs also reflected the expressions of COL6A1 were raised as the increment of P4HA1 (Figure 4C), and immunofluorescence analysis of mouse tumor samples showed that the COL6A1 expression was controlled by P4HA1(Figure 7), which was consistent with the experimental results in vitro.