TRPM4 and atrial fibrillation: In the non-degenerated IVDs, TRPC1, TRPC2, TRPM7, TRPML1–3, PKD1, TRPP1 (PKD2), TRPV1, TRPV3 and TRPV4 were detected in both, NP and AF samples, whereas other TRP channels were only detectable in either region: TRPC6 (AF), TRPM4 (NP), TRPM6 (NP), and TRPV5 (NP).