Spontaneous differentiation. This figure shows the average relative VASA expression in 3 hESC lines (VUB01, VUB02 and VUB07) over time, during spontaneous differentiation as EBs, respectively in undifferentiated (undiff) cells and after 1, 3, 5, 7, 10 and 14 days of differentiation. Time points marked with different letters were significantly different after one-way ANOVA (undiff vs. d5: P < 0.001; undiff vs. d7, d1 vs. d5, d3 vs. d5, d5 vs. d14: p < 0.01; d5 vs. d10: p < 0.05). (hESC human embryonic stem cell, EB embryoid body)