mAb 3C2 specific to the fiber-2 protein could efficiently block infection by FAdV-4, providing strong evidence that the fiber-2 protein plays vital roles in mediating FAdV-4 infection, possibly through binding to its cell receptor. Fiber-2-interacting proteins (including the cell receptor) are currently being identified using mAb 3C2 through Co-IP and Mass Spectrometry analyses. In addition, the mAb 3C2 generated here and its identified epitope may be useful for the development of passive immunotherapy and rapid diagnostic tests, such as antigen-capture ELISA or peptide-based ELISA.