IPA functional analysis and first top network associated with the Cluster 2. (A) Bar chart shows key function associated with genes found to be down-regulated (cluster 2) at the 12th passage of WJ-MSCs as compared to cells at the 4th passage. (B) Network cluster 2: in gray are represented the down-regulated genes at the 12th passage of WJ-MSCs in vitro expanded, as compared to the same cells at the 4th passage. Transcripts not modulated along with the different passages are represented in white. Arrows indicate that a molecule acts on another molecule, while lines indicate a bind between two molecules.