HSPA5 and cancer: Previously, we have monitored Bip/GRP78 promoter activity during cancer cell growth by real‐time imaging at the level of the single cell using a bioluminescence microscopy system, in which a cooling charge coupled device (CCD) camera was successfully combined with a microscope as a new optical system.18 Bioluminescence and morphology was detected and observed at the single cell level using this system, and was important in selecting live cells and excluding false positives.