MGMT and pachyonychia congenita: Low MGMT immunoreactivity is associated with sensitivity to TMZ treatment in patients with PC and aggressive PA, and MGMT expression has been described as a biomarker to predict tumor response to TMZ in case reports and small case series.[41] However, Preusser et al[42] observed poor correlation between MGMT immunoreactivity and MGMT promoter methylation status, and no significant association between MGMT expression and prognosis for glioblastoma multiforme patients.