Figure 2. The largest source of variation in the transcriptomics data is associated with gestational age across samples.

Prinicipal component analysis using the RNA expression microarray data across just the normal birthweight samples (A) or across all samples (B), returned principal component 1 (x-axis) which has a significant correlation with gestational age of the samples. Samples are classified into high birth weight group (>3700 g) in orange; low birthweight group (<2500 g) in green; normal birthweight and gestational age less than or equal to 37 weeks in blue; or normal birthweight and gestational age more than 37 weeks in red.