STAT3 and cancer: N-acyl-hydrazones 5-nitrofurans also exhibit anticancer properties, inhibiting different pathways in cancer cell cycles: signal transducer and activator of transcription 3 (STAT3) (nifuroxazide [84], nifuratel [85]), aldehyde dehydrogenase 1 (ALDH1) (nifuroxazide [86]) and nuclear factor kappa B signalling (furazolidone [87]) (Figure 2 and Figure 3).