HSP90B1 and colorectal carcinoma: Although further studies are required, our finding that GRP94 IgG has better efficacy in inhibiting the growth of cetuximab-sensitive Caco-2 cells compared to cetuximab also shows the possibility that the antibody targeting of cell surface GRP94 might simultaneously inhibit CRC cell growth in both cetuximab responders and cetuximab nonresponders.