Hi Hussein, there are 3 recent papers reporting variations of defensin genes in human tumors. These results could suggest future practical applications.
1) Abe S. et al. Copy number variation of the antimicrobial-gene, defensin beta 4, is associated with susceptibility to cervical cancer. J Hum Genet. 2013;58:250-3 (here enclosed)
and two free PubMed article:
2) Winter J. et al. Human α-defensin (DEFA) gene expression helps to characterise benign and malignant salivary gland tumours. Winter J. et al. BMC Cancer. 2012;12:465.
3) Taudien S. et al. Association studies of the copy-number variable ß-defensin cluster on 8p23.1 in adenocarcinoma and chronic pancreatitis. BMC Res Notes. 2012;5:629.