Figure 4.
Principal component analysis (PCA) for the concentration of various immune factors in human milk. Top panels (A–C) represent separation into bidimensional maps, each one representing different dimension combinations. Arrows indicate variable factors contributing the most to the separation of the samples along the map. Variables with a cos2 > 0.2 are represented in blue and those with a lesser contribution to the graph are indicated in red dashed arrows. Lower panels (D–F) represent the distribution of the samples’ centroids of the different geographical locations (pink letters) along the same dimension combinations displayed in the respective upper panels (A–C). Ellipsoids include at least 50% of the individuals belonging to each of the represented categories, which include VHHD, HHD, MHD, and LHD countries [United Nations Development Program; (28)].