KP1019 (indazolium trans-[RuCl4(ind)2]), a Ru(III) prodrug, undergoes reduction under hypoxic tumor conditions to Ru(II), leading to ER Ca2+ depletion and activation of IRE1 and PERK, culminating in CHOP-mediated apoptosis. This evidence concerns the gene EIF2AK3 and neoplasm.