HSPA5 and cancer: We focused the further functional analysis on this protein, because (i) it is the master regulator of the UPR, which is activated in many different cancers (Wang et al, 2009), (ii) it was found in the BioID screen with an SP of 1, (iii) its close proximity with NRF3 was verified for the endogenous proteins (Fig 5H); and (iv) overexpression of HSPA5 promoted malignancy in other types of cancer (Wang et al, 2009; Wang & Kaufman, 2014).