CTLA4 and neoplasm: To investigate whether HSP90 inhibition and immune checkpoint blockade treatments modulate the immune cell population infiltrating the tumor, C57BL/6 mice were treated with vehicle, ganetespib, anti-CTLA4, or the combination of ganetespib and anti-CTLA4, starting day 7 after inoculation with MC38/gp100 tumors (Fig. 4a).