Figure 1. RNA expression pattern changes in samples from climbers at four different altitudes.

(A) Illustration of the climbing path and the sampling locations with average SpO₂ and HR of four subjects. (B) PCA of all samples based on expression profiles of all genes measured by RNA-seq. The four colors represent the four different altitudes. (C) Hierarchical clustering of all samples based on expression profiles of all genes measured by RNA-seq. Samples are named in the format of ‘Climber ID-altitude’. The expression value for each gene is indicated by color intensity, with red representing high expression and green representing low expression.