Fig. 4

Hybrid clone cells possess a unique mammosphere formation capacity. a) BoxPlot diagram of the mammosphere size, whereby only mammospheres > 60 μm were included. b) Bar graph of the mean ± STD number of mammosphere (> 60 μm). Two M13SV1-EGFP-Neo controls are shown here because M13HS and M13MDA435 hybrid clones and M13MDA231 hybrid clones were independently analyzed from each other. Shown are the data of at least three independent experiments. * = p < 0.05, *** = p < 0.01 (in relation to M13SV1-EGFP-Neo human breast epithelial cells); † = p < 0.05, ††† = p < 0.001