Western blots from primary MEM cell lysates were performed as described31. Antibodies for ALX3 (1:5000 dilution)31, FOXO1 (L27, 1:1000 dilution; Cell Signalling Technology, Beverly, MA, USA) and β-actin (AC-15, 1:10000 dilution; Sigma-Aldrich) were used for detection. Where indicated, films were scanned and densitometry measurements of bands were performed using ImageJ software (http://rsbweb.nih.gov/ij/).