These considerations notwithstanding, control of dorsoventral trunk pattern by Tbx15 shares certain features with control of dorsoventral limb patterning by Lmx1b, a LIM domain transcription factor that acts downstream of Wnt7a and En1 (Riddle et al. 1995; Vogel et al. 1995; Cygan et al. 1997; Logan et al. 1997; Loomis et al. 1998; Chen and Johnson 2002).