The IgG4-Fc mutant EQ linker exhibits reduced binding to Fcγ receptors (FcγR) and superior anti-tumor efficacy and persistence in immunodeficient mice24, and co-expresses enhanced green fluorescent protein (eGFP) linked with the T2A self cleaving peptide, which can be used as a transduction marker. This evidence concerns the gene FCGR2A and neoplasm.