Furthermore, the significant negative correlation of preoperative GFAP serum levels with the time until tumor recurrence (progression‐free survival [PFS]) for grade III and IV astrocytoma patients (Kiviniemi et al., 2015) indicates that factors in the biology of the tumor contribute to the GFAP serum levels, rather than surgical damage only. The gene discussed is GFAP; the disease is astrocytoma (excluding glioblastoma).