Wellberg et al. [40], on the other hand, showed that GLUT1 expression was higher in ductal carcinoma in situ compared to normal breast tissue but lower in invasive versus in situ lesions, suggesting that the requirement for GLUT1 was predominant in early cancer lesions but decreased with tumor progression [40]. The gene discussed is SLC2A1; the disease is ductal breast carcinoma in situ.