Gonheim et al. demonstrated that inhibition of this progressive methylation by DNMT3A knockout preserved effector function even in LCMV Clone 13 infection, and that inhibition of methylation together with PD-1 blockade synergistically enhanced proliferation of virus-specific cells, mediated in part through prevention of methylation at the myc locus that would normally act to prevent TEX from initiating cell cycling [145]. The gene discussed is PDCD1; the disease is infection.