Together, our results indicate that the absence of CSPα/DNAJC5 by itself does not cause the pathological lipofuscinosis that, on the other hand, is clearly observed in the transgenic mice expressing the mutant forms of CSPα/DNAJC5 causing Kufs disease/CLN4 in humans. The gene discussed is DNAJC5; the disease is adult neuronal ceroid lipofuscinosis.