FAP and acquired polycythemia vera: Some of these methods rely on the use of various primer systems like the FAP 59 and FAP 64 degenerate base containing primer system (Sias et al., 2019), the double nested PGmy,9/11 and Gp+5/+6 primers (Fuessel Haws et al., 2004), and the Soltar method for the identification of a select number of PV types with emphasis on the oncogenic PV types (Sotlar et al., 2004).