KRT7 and Kaposi's sarcoma: RT-PCR detection of viral circRNAs in freshly frozen (FF) or optimal-cutting-temperature (OCT) embedded KS tissue samples showed that 14/17 (82.4%) samples were positive for circ-vIRF4 expression and 5/17 (29.4%) positive for circPAN/K7.3 using a divergent primer pair that can detect most circRNAs in both PAN RNA and the anti-sense K7.3 region (Table 1).