HLA-A*02 allele is associated with poor prognosis in different cancers such as ovarian, prostate, melanoma and lung cancer. In the same time, in advance ovarian cancer, HLA-A2 is a negative clinical prognostic factor and it is phenotype overrepresented in both ovarian and prostate cancer in Swedish patients compared to the normal population. At the genetic level, it is possible to consider a linkage of HLA-A2 allele to putative onco- or tumour suppressor genes and could explained the increased potential for oncogenic transformation of cells and thus an increase mortality in these patients. At epigenetic level, it is speculated that a specific HLA-A2 micro RNA downregulate the HLA antigen expression in the HLA-A2 patients. During initial oncogenesis, the transformed cells may upregulate transcription of the major histocompatibility complex genes which served to absorb and engage the pool of miRNA. Potentially, this may prevent translation of HLA antigen message which impedes expression of HLA antigen and immune recognition. Moreover, normal regulatory functions of the miRNA are also compromised as the “decoy” transformed cells absorb and engage the available pool of miRNA.