S-Phase Fraction
Definition of S-Phase Fraction:
A measure of the percentage of cells in a tumor that are in the phase of the cell cycle during which DNA is synthesized. The S-phase fraction may be used with the proliferative index to give a more complete understanding of how fast a tumor is growing.

The percentage of cells in a sample currently undergoing mitosis.
S-Phase Fraction is part of the Properties or Attributes group
S-Phase Fraction is also know as:
Cell Proliferative Activity
Cellular Proliferation Rate
Labeling Index
Mitotic Index
Proliferation Index