PTPA and lung cancer: Enriched TICs from A549 (Supplementary Fig. 8a), an anchorage-dependent human lung cancer cell line, increased tumour initiation (Supplementary Fig. 8b), suspension-survival ability (Supplementary Fig. 8c), the PP2A-STAT3-Col XVII-laminin 5 pathway (Supplementary Fig. 8d) and the colocalization of Col XVII and laminin 5 (Fig. 8e).