ARSB and mucopolysaccharidosis type 6: Since ArsbCOIN/COIN mice replicated many of the hallmarks of MPS VI (11, 14, 15), we explored whether rescue of key phenotypes is possible when Arsb is restored at different time points, by delivering tamoxifen to cohorts at juvenile (P7), early adolescence (P21), or adult (P56–P70) stage.