The expression patterns of RHOXF2 determined by qPCR in humans(a), chimpanzee(b), white-browed gibbon(c) and rhesus macaque(d). The relative expression levels were calculated by setting the expression level in testicle as "1". For the human samples, Brain 1(40 yrs), Brain 2 (28 yrs), Brain 3 (newborn, 1 month) and testicle (76 yrs) are all male individuals. The human embryo is a 36-weeks female. The ages of the nonhuman primate samples are 2 yrs for the male chimpanzee, 6 yrs for the male white-browed gibbon and 20 yrs for the male rhesus macaque. "NC" refers to negative control. The detailed sample information of the nonhuman primate species is described in Materials and Methods.