A prominent feature of the human brain is the "gyrification" (folding of the cerebral cortex into gyrus and sulcus), which helps to pack larger cerebral cortex into the restricted skull volume, and thus has contributed to the brain expansion and evolution. Probably all of you have seen the picture or cartoon of the human brain with wrinkling surface (that is gyrification), however, have you ever imagined how this unique structure emerges during development? In this lecture, by introducing a paper which identified a human-specific gene and its role in gyrification of the cerebral cortex, I will discuss how scientists have been seeking for the molecular and cellular mechanisms that create this characteristic anatomical feature of our brain.