The loss function of PPT1, which depalmitoylates GFAP, results in an elevated level of palm-GFAP in PPT1-KI mice, and therefore accelerates astrocyte proliferation and eventually leads to serious astrogliosis and dampen neurodegenerative pathology in INCL (Fig. 6). Here, PPT1 is linked to infantile neuronal ceroid lipofuscinosis.