When added to human osteosarcoma U2OS cells engineered to express a CALR‐green fluorescent protein (GFP) fusion protein, DACT (used around the IC60 for these cells, i.e., at 0.5 and 1 μM, Appendix Fig S1) caused peripheralization of the green fluorescence to the same extent as the positive control, MTX, as determined by videomicroscopy (Fig 2A–C). This evidence concerns the gene CALR and osteosarcoma.