PTHLH and neoplasm: Over expression of many cluster 2 genes in stage II or later is not surprising as gene descriptions provided by Affymetrix probe set annotation [17] reveals some of these genes such as PTHLH, homeo box B7, a transcriptional activator that functions in angiogenesis, immediate early response 3, angiopoietin-like 2 are known to play a role in angiogenesis and others including several collagen family genes are involved in extracellular remodeling during tumor spread.