EPHA2 and colonic neoplasm: When tested on the mouse EphA2-expressing colon cancer cell line MC38-CEA, only IgG28 showed high affinity cross-reactivity to the murine EphA2 receptor Kd = 1 nM (Figure 1(b)) and was competitive with the ephrinA1-Fc ligand with an IC50 = 0.89 nM (Figure 1(c)).