HCN2 and schizophrenia: A second gene, HCN2, coding for a hyperpolarization-activated cation channel crucial in pacemaker activity in the heart and brain (33), showed differential expression and accessibility (DE and DA risk gene) in Exc_L2-3 among extreme–genetic risk groups for schizophrenia PRS (Figs. 4, C and E, and 6, F and G), with no significant dysregulation in other cell types (Fig. 6H).