GPC1 and neoplasm: Overexpression of miR‐96‐5p and miR‐149 significantly decreased GPC1 expression in HT‐29 and HCT‐116 cells, xenograft tumours, plasma in mice bearing HT‐29 and HCT‐116 tumours, and the secretion of GPC1+ exosomes from the HT‐29 and HCT‐116 cells and xenograft tumours.