Fig. 5

M13HS hybrid clone cells possess a unique mammosphere formation capacity. a Mean diameter of originated mammospheres, b mean mammosphere count. Shown are the means of at least five independent experiments using cells of different passages. Statistical analysis was performed using an unpaired two-tailed Student’s t-test: * = p < 0.05, ** = p < 0.01, *** = p < 0.001 (vs. M13SV1-EGFP-Neo cells); † = p < 0.05, †† = p < 0.01, ††† = p < 0.001 (vs. HS578T-Hyg cells). c Shown are representative images of mammospheres derived from the indicated cell lines. Note the markedly increased size of M13HS-2 mammospheres. Bar = 100 μm