ERBB3 and cancer: Since the first construct HER2-targeting affibody molecule ZHER2:342 was produced and confirmed to bind to HER2-positive cancer cell lines [24], several similar affibody molecules targeting EGFR [23,24], HER3 [27,28], IGF-1R [42], HIV-1-gp120 [43] and HPV16E7 [30,31] have been reported and also applied to image several tumour- associated molecular targets, such as HER2[25, 44], EGFR[45,46], HER3[47].