In solid tumor oncology, early phase trials of BiTE therapy have encountered multiple challenges, including the lack of specific target antigens, tumor heterogeneity, and “on-target, off-tumor” toxicities.72,73 However, one promising target antigen to emerge in RCC may be ectonucleotide pyrophosphatase/phosphodiesterase 3 (ENPP3), given its specific expression on RCC cells and minimal expression in healthy tissue. The gene discussed is ENPP3; the disease is renal cell carcinoma.