Previous works revealed the presence of the nPKC enzyme p105 in hemocytes of M. galloprovincialis Lmk. Specific mussel antibodies were obtained from mouse and used in confocal microscopy and Western blotting. These techniques allowed the observation of p105 cytosol-to-membrane translocation induced by TPA for the first time in hemocytes of molluscs. The incubation of mussel immune cells with TPA for longer than 30 min also triggered a down-regulation process. Mussel hemocytes are an excellent model to study the molecular processes of innate immunity.