As shown in Fig. 5a, the fluorescence signal in tumours, acquired with an exposure time of 2000 ms, was minimal for conjugates 4 and 5 (56.4 ± 4.1 and 60.9 ± 6.3 AU, respectively), rendering them ineffectual for in vivo evaluation of FRα expression. The gene discussed is FOLR1; the disease is neoplasm.