When plants such as Arabidopsis are under canopy shade, the most prominent response is the elongations of stems/petioles. In this issue, Yu et al. (pp. 757–769) report that shade avoidance 2 (sav2) mutant (the bottom one in two SEM photos, and the right one in two seedlings) exhibits short and swollen hypocotyls when grown in shade. SAV2 encodes a β-tubulin, suggesting cMTs is cortical in regulating anisotropic cell growth.