The pericytes used in these experiments were probably in which phase of the cell cycle

Answer: Interphase

The pericytes are in the interphase of the cell cycle. This is the phase of the cell cycle between each cell division and is the phase in which the cell obtains nutrients, grows, reads its DNA, and conducts other normal cell functions including the arrest of the growth of the pericytes that were treated so that they would not divide but continue to function normally.