GSTM1 and ischemia: From Fick’s equation, Ca-vO2 resulted 164.1 mL L-1, corresponding to an O2 extraction of 76.5%, similar to the fractional O2 extraction (Δ[deoxy (Hb + Mb)]peak/Δ[deoxy (Hb+Mb)ischemia] = 75.2%) estimated by NIRS.