These factors include the design of the CAR construct [8], the manufacturing protocol [9], the frequency of functionally active T cells in the manufacturing and infusion products [10], the T cell phenotype [11,12], and the CD4+/CD8+ subset composition [12,13] in the infusion product, the tumor burden [10], the tumor microenvironment [14,15] and the dose and type of lymphodepleting chemotherapy [16,17]. Here, CD4 is linked to neoplasm.