In turn, 4,6-substituted-1H-indazole derivatives and 4-bromophenylhydrazinyl benzenesulfonylphenylureas showed high activity against both IDO and TDO and inhibited cancer growth and reduce the tumor weight in-vivo in the CT26 xenograft model (Table 1) [96,100,102]. Here, TDO2 is linked to neoplasm.