HCN1 and Alzheimer disease: Another study analyzed the differential expression of genes between Alzheimer’s and non-Alzheimer’s diseases and found that the expression of C-Met, NPTX2, neurogenic differentiation factor 6 (NEUROD6), hyperpolarization-activated cyclic nucleotide-gated potassium channel 1 (HCN1), etc., significantly decreased in Alzheimer’s disease18.