This effect was comparable to treatment with the specific CaMKII inhibitor AIP (HFpEF + vehicle vs. HFpEF + AIP; −45.69 ± 7.41 A*ms*F−1 vs. −16.75 ± 4.7 A*ms*F−1, N = 5 vs. N = 5, P = 0.0187, Figure 5A and B), suggesting a role of CaMKII for increased late INa in atrial cardiomyocytes of HFpEF patients. The gene discussed is AIP; the disease is autoimmune pancreatitis.