Targeting of lamin B1–associated loci does not take place during interphase. Targeting cells stably expressing histone H2A-YFP (green) were induced to express LacI-mCherry–Lamin B1 (red, arrow) and cells with a nontargeted lamin B1–bound locus were selected for imaging. Still images (a–o) are shown from an interphase time series (0–24 h, early G1 to late G2 phase). Images are projections of deconvolved z stacks taken every 20 min. Bar, 5 μm.