PRC1 and lung cancer: To begin to address whether proliferation of K-RAS mutant lung cancer cell lines depends on regulators of the mitotic spindle midzone, we used a multifunctional lentiviral vector to establish stable H23 and H460 cell lines that express doxycycline-inducible small hairpin RNAs (shRNAs) to deplete mitotic kinesins or PRC1 by RNAi (Figure 2A).