Cardiac tissues from explanted hearts of patients with end-stage HF (Failing) contained decreased PFN1 transcript levels (0.55 ± 0.04 a.u. n = 9) compared with donor hearts (Healthy, 1.05 ± 0.21 a.u., n = 8; see Supplementary material online, Table S1 and Figure S1D). Here, PFN1 is linked to hydrops fetalis.