Bystander effect. Illustration of the scFv62-TRAIL bystander effect. Binding of scFv62-TRAIL to KV10.1 results in the membrane-bound form of TRAIL. Thereby, it is possible to induce apoptosis in the same cell (autocrine) or in a neighboring cell (paracrine) independently of KV10.1 expression. Targeting of KV10.1-negative cells is defined as bystander effect.