Improvements have been achieved by antagonizing co-inhibitory signaling molecules such as PD-1 by co-infusion of signal blocking antibodies with engineered T cells [5, 339], or by modification of T cells expressing the PD-1 negative receptor; the anti-tumor efficacy of an IL-6 and PD-1 antibody blockade combination [340] and knockdown of the minus-regulatory protein site using precision editing with CRISPR/Cas9 also enhanced the anti-tumor function of transgenic T cells [341]. The gene discussed is IL6; the disease is neoplasm.