HSPA5 and neoplasm: In contrast to the clinically widely administered platinum‐based anticancer agents that target DNA, this ruthenium(III) anticancer drug candidate acts on other biomolecules.[4] Recently, the down‐modulation of the glucose‐regulated protein of 78 kDa (GRP78, HSPA5) combined with endoplasmic reticulum (ER) stress, as well as the induction of reactive oxygen species (ROS) emerged as accepted drug effects in several 2D and 3D tumour models.[5] However, the mechanism of ER‐stress induction and possible targets of BOLD‐100 remained rather elusive despite intense research efforts.