By constructing Th17/Th1 cells, which is a group of cells that possesses the stem cell characteristics of Th17 cells and the tumor-suppressive IFN-γ secretion abilities of Th1 cells, these composite cells exhibit a metabolic state characterized by suppressed glycolysis and enhanced glutamine breakdown and exert high expression of histone deacetylase sirtuin-1 (SIRT1) and Forkhead box O1 (FOXO1) under the conditions of a CD38 inhibitor and increased nicotinamide adenine dinucleotide+ (NAD+). Here, CD38 is linked to neoplasm.