Figure 2. In vitro comparison of the clonogenic potential of stem-like cancer cells and WERI-Rb1 cells. A: The WERI-Rb1 cells grew in loose grape-like clusters when cultured in serum-RPMI-1640 medium. Scale bar=50 μm. B: Stem-like cancer cells (SLCCs) were plated as single-cell suspensions in 96-well plates. The expanded clones are displayed after 14 days. Scale bar=50 μm. C: The clone formation efficiency of WERI-Rb1 cells and SLCCs after 14 days was 15.26±0.93% and 31.70±1.89%, respectively (**p<0.01). The graph shows the mean±SD (n=3).