SYD985 has considerable bystander killing effect for two reasons—DUBA itself is membrane-permeable after being released from the lysosome, and SYD985 cleaving proteases, like cathepsin B, are usually produced by tumor cells, meaning they are present in the extracellular milieu, thereby maximizing this ADC’s effect in surrounding tumor cells [94]. Here, OTUD5 is linked to neoplasm.