Cyclophosphamide resistance. Employing 2D-DIGE analysis, Thoenes et al. observed a significantly upregulated ANXA3 expression in cyclophosphamide (CPA)-resistant PC3-D3 and PC3-D4 prostate cancer cells compared to the chemo-sensitive wild type PC3 cell line (Thoenes et al., 2010). The gene discussed is ANXA3; the disease is prostate cancer.