The upregulated proteins in PSP frontal cortex were associated with the synaptic membrane (ANXA1 and ANO6), the presynapse (including GABRA3, SYN1 and SYT5), the synaptic cleft (LAMC1) and the postsynapse (including GABRA3, CRTC1, MAPK1 and MAP2K1). Here, MAPK1 is linked to supranuclear palsy, progressive, 1.