Spheroid volume increase of NSC and UW228-3 cells as a function of initial seeding number.

<p>Volume increase % = 100*(V<sub>day7</sub>−V<sub>day1</sub>)/V<sub>day1</sub>. NSCs grew more in a week than UW cells, reaching maximum growth increase of 600% for seeding 1000 cells per spheroid, whereas the maximum growth increase for tumour cells was around 170% for 2000–5000 cells/spheroid.</p>