CA9 and neoplasm: To assess the efficiency of in vivo targeting of CA IX, we performed a comparative biodistribution analysis with SIP(A3), SIP(HyHEL-10) used as negative control and SIP(L19), a clinical-stage antibody which recognises tumour neo-vascular structures (Borsi et al, 2002; Berndorff et al, 2005; Tijink et al, 2006; El-Emir et al, 2007b; Sauer et al, 2009).