“…Tumor cells in pheochromocytomas retain their ability to express neuronal and neuroendocrine proteins including neurofilament protein (Osborn et al, 1982;Lehto et al, 1983;Miettinen et al, 1985Miettinen et al, , 1987Trojanowski and Lee, 1985), chromogranin A (Lloyd et al, 1985(Lloyd et al, , 1986Tischler et al, 1987;Hacker et al, 1988;Fraga et al, 1993), synaptophysin (Gould et al, 1987;Miettinen, 1987;Fraga et al, 1993), ␥-enolase (neuronspecific enolase) (Tapia et al, 1981;Hacker et al, 1988;Fraga et al, 1993), PGP9.5 (Rode et al, 1985), catecholamines and their synthesizing enzymes (Lloyd et al, 1986), and multiple neuropeptides (Mendelsohn et al, 1982;DeLellis et al, 1983;Lloyd et al, 1984;Lundberg et al, 1986;Tischler et al, 1987;Hacker et al, 1988;Sano et al, 1991;Polak, 1993). Several in vitro studies using the PC12 rat pheochromocytoma cell line have demonstrated the presence of neuronal cytoskeletal proteins (reviewed in Katsetos et al, 1998B), including neurofilament protein (Virtanen et al, 1981;Lee et al, 1982), microtubule-associated proteins (MAPs) (reviewed in Katsetos et al, 1998B), and the neuronspecific class III -tubulin isotype (Asai and Remolona, 1989;Katsetos et al, 1998B), ascertaining its neuronal consanguinity.…”