IL6 and acute lymphoblastic leukemia: Yet, few studies have reported data regarding the treatment of extramedullary B-ALL relapse, especially both in skin and testicle, with CAR-T therapy.<h4>Case presentation</h4>Here we reported a single case of a patient with relapsed B-ALL in skin and testicle who was successfully treated by the shRNA-IL6-modified anti-CD19 CAR-T(ssCAR-T-19) therapy.