SP1 and ovarian cancer: Since SP1 and its DNA-binding activities are inducible under oxidative stress and DNA-damage (Ryu et al., 2003), and assuming there are SP1/AP2 binding sites within this region as suggested by Izutsu et al. (2008), it is possible that under chemotherapeutic insults, hypomethylated TUBB3 promoter regions with enhanced SP1 signalling may contribute to aberrant TUBB3 expression in ovarian cancer.