CDC73 and gonorrhea: However, CDC73 mutational analysis and parafibromin immunostaining has been reported to be more reliable, with: CDC73 mutations being identified in >75% of PCs but in <1% of PAs (Shattuck et al., 2003b; Krebs et al., 2005; Gill, 2014); and loss of nuclear parafibromin immunostaining occurring in >95% of PCs, but in <1% of PAs (Tan et al., 2004; Gill et al., 2006; Meyer‐Rochow et al., 2007).