TMEM18 tissue distribution in rat, mouse and fly. Relative mRNA expression of the TMEM18 gene was investigated in three species. Means are relative to the tissue with the lowest expression (set to 1) in the rat and mouse. The expression was measured with real-time PCR for A. Rat and B. Mouse, whereas the expression of TMEM18 in C. fly was received from the FlyAtlas microarray database, the expression is relative to the whole fly. All error bars represent SEM.