PTGS2 and pachyonychia congenita: In a separate study, also using the Illumina 450K array, Stott-Miller et al. [58] investigated the methylation status of a set of 14 previously reported candidate methylation markers for PC prognosis (ABHD9, APC, ASC, CD44, CDH13, GPR7, GSTP1, HOXD3, MDR1, PITX2, PTGS2, RARB, RASSF1A, and RUNX3) in 407 PC specimens from RP patients.