Separation by FACS and cell cycle assay of RS-MSCs and SR-MSCs from 5-day cultures of human MSCs initially plated at 100 cells/cm². (A) Re-assay of FS/SS of RS-MSCs after sorting for low FS/low SS.³¹  (B) Re-assay of SR-MSCS after sorting for high FS/high SS. (C) Cell cycle analysis of RS-MSCs. (D) Cell cycle analysis of SR-MSCs.