HSPA5 and head and neck squamous cell carcinoma: Whilst radiation increased the trypsin sensitive pool of GRP78 on the surface of both BHY and FaDu cells, the amount of trypsin resistant intracellular GRP78 did not change The same results could be observed in the HNSCC cell lines CAL-33 and SCC131 (Supplementary Figures S1A–C).