ERCC1 and progeroid syndrome: Both the mSFI and CFI were applied in male (N = 4) and female (N = 4) Ercc1−/Δ mice as well as male (N = 4) and female (N = 4) ERCC1 wt mice at 8 weeks of age to anticipate the rapid physical decline observed in these progeria models (Fig. 4B, D; Supplementary Fig. 1C).