IL3RA and neoplasm: To target CD123, Shu-Ru Kuo et al. have engineered a CD123 × CD3 bispecific scFv immunofusion to target CD123+ LSCs in vitro, which contained an antiCD123 scFv fused at the N-terminus of human IgG1 hinge-CH2-CH3, and an antiCD3 scFv fused at C-terminus; the molecular weight of 140 kDa would affect their penetration into tumor tissue [17].