NPPA and hydrops fetalis: Early- and late-treated PLN-R14 Δ/Δ mice demonstrated a similar ASO-mediated reduction in PLN levels, but at the start of late PLN-ASO therapy (7 weeks of age), PLN-R14 Δ/Δ mice had developed worse HF than when treatment was started in the ASO-early group (6 weeks of age), resulting in worse LV function, higher ANP levels and more fibrosis formation in the ASO-late group at the study endpoint.