Numerous studies have reported that activation of the MAPK signaling pathway promotes castration resistance and tumor progression in PCa.[25, 26, 27, 28] Additionally, immunohistochemistry (IHC) staining suggested that in subcutaneous tumors, the presence of ECM1 activated the MAPK signaling pathway; similarly, in ENZ‐treated tibial tumors, the MAPK signaling pathway was also activated, whereas ECM1 pAb inhibited this process (Figure 3D). Here, ECM1 is linked to neoplasm.