Given that KLF2 is a tonic repressor of inflammation, we assessed Klf2 mRNA levels by quantitative RT-PCR (qPCR) in peripheral blood leukocytes harvested from a cohort of HF patients and non-HF controls (Supplemental Table 1; supplemental material available online with this article; https://doi.org/10.1172/JCI147191DS1). This evidence concerns the gene KLF2 and hydrops fetalis.