Absence of PLZF expression in cells signs their stemness state. (A) Expression profile of PLZF during the chondrogenic differentiation of MSCs as assessed by microarray analysis. At day 0, absence of PLZF expression was defined as 1, and this was used to calculate the relative expression at the remaining time points. (B) PLZF expression profile in human MSCs, ESCs, iPSs, adipose tissue, skeletal muscle, and trachea as reported in the Amazonia website. The signal intensity is shown on the y axis as arbitrary units determined by the GCOS 1.2 software (Affymetrix). When indicated, the mean expression is significantly different from that in MSCs, hESCs, and hiPS. (C) PLZF-related network was reconstructed by using the Ingenuity Pathways Analysis Software (IPA) software where PLZF acts upstream of Runx2 and regulates downstream genes. Blue-shaded genes are genes identified to be involved in chondrogenesis, grey-shaded genes either involved in osteogenesis or adipogenesis, and unshaded genes are those associated with the identified genes based on pathway analysis.