Visual representation of PCA results for the MSC dataset, without (A) and with preclustering (B). The dots (scores) represent GO categories or subgroups, and the arrows (loadings) are the treatments with which the categories can be correlated (indicated with DEX, BMP, VIT and UNT). Only a subset of GO classes is depicted, to focus on cell differentiation and osteogenesis. In Figure 5A the 24 original GO classes are shown and in Figure 5B the 79 subclasses. The stars identify the GO term GO:0001501 (skeletal development).