2.9. Immunofluorescence staining

Indirect immunofluorescence (IF) staining followed standard protocols as described in previous studies [15]. The following primary antibodies were used: mouse CD98hc (either MEM-108/BioLegend, or UM7F8/BD Pharmingen), mouse LAMP1 (H4A3, BioLegend), rabbit LAMP1 (D2D11, CST), mouse CD44 (BJ18, BioLegend), mouse CD59 [p282 (H19)] (BioLegend), mouse CD147 (HIM6, BioLegend) and mouse alpha tubulin (DM A1, Thermo Fisher). For fluorescent visualisation of primary antibody binding, matching secondary antibodies labelled with either Cy3 or Alexa Fluor^® 555 or DyLight^® 488 obtained from Jackson ImmunoResearch (West Grove, PA, USA) or BioLegend were used. 4′, 6-Diamidin-2-phenylindol (DAPI, 1μg/mL, Sigma) was routinely used to counterstain nuclei but is not shown in every image compilation. In some experiments actin fibres were visualised with phalloidin staining using phalloidin–tetramethylrhodamine B isothiocyanate (Sigma). A Leica DM 4000 fluorescence microscope (Wetzlar, Germany) was used to monitor and document IF-stained cells.