293 FANCC E2 cells were left untreated (control) or were treated with vehicle only (DMSO), MG132 (20 μM), or lactacystin (10 μM) for 24 hours in the presence or absence of 1.3 mmol/L HU. Ten percent of the cells from each experimental condition were analyzed for DNA content by flow cytometry, and the remaining cells were processed for measurement of FANCC expression by immunoblot (Figure 6). The tabulated values indicate the percent of cells in each phase of the cell cycle.