A study investigating the expression of COX-1 and COX-2 in classic and epidemic forms of Kaposi Sarcoma (KS) tissue showed that COX-1 and COX-2 were overexpressed significantly in classic and epidemic KS compared with control skin tissues suggesting that COXs may be involved in the pathogenesis of KS (Rossiello et al., 2007). Here, PTGS1 is linked to Kaposi's sarcoma.