The ssCART-19 DNA was mainly concentrated in the liver within 3 hours, and was widely distributed in most of the organs/tissues for 4 weeks after administration, demonstrating that ssCART-19 with shRNA-IL-6 gene knockdown prolongs the survival time of tumor-bearing mice with a potential inferior risk of immunotoxicity and tumorigenicity (42). This evidence concerns the gene IL6 and neoplasm.