The response to RhoA activation is not strongly cell-cycle regulated. Images of photoactivated metaphase HeLa cells (A) and noncontractile (200 nM BI 2536) anaphase HeLa cells without (B) and with (C) 5-(N-ethyl-N-isopropyl)amiloride (EIPA; 37.5 µM, 30 min). Nonadherent interphase NIH3T3 cells photoactivated only locally (960-ms pulse; D) or supplemented with global illumination (10-ms pulse; E). Quantification of ingression (%; F) and constriction rate (µm/min; G) of nonadherent interphase NIH3T3 cells illuminated as in D and E. Bars, 5 µm.