PTPA and neoplasm: To demonstrate that the increased suspension-survival ability is essential for tumour formation of TICs and has clinical relevance, we first showed that blocking the PP2A-S727STAT3-Col XVII pathway inhibited tumour initiation by TICs (Fig. 7a) and activation of the pathway enhanced tumour initiation in bulk tumour cells to the same extent as in TICs (Fig. 7a).