Transcriptional factors in response to hypoxia. Examples of Western blots bands normalized to β-actin (with each corresponding well) are shown. Units are expressed relative to the β-actin content. (A) HIF-1α, hypoxia-inducible factor 1-alpha; (B) NF-κBp50, nuclear factor kappa-light-chain-enhancer of activated B cells; (C) EPO, erythropoietin. Statistically significant differences between groups are presented with asterisks (*, vs. NOR), crosses (+, vs. ASH) or hashtags (#, vs. IHH). One symbol indicates p < 0.05, two symbols p < 0.01 and three symbols p < 0.001. F-values after running one-way ANOVAs with Bonferroni’s post hoc multiple comparison tests were: F = 3.96 (HIF-1α), F = 1.01 (NF-κBp50) and F = 11.98 (EPO). Animal experimental groups are abbreviated as NOR, normoxic; ASH, acute severe hypoxia; IHH, intermittent hypobaric hypoxia; IHH+ASH, intermittent hypobaric hypoxia followed by acute severe hypoxia.