In female SERT‐overexpressing (SERT+) mice, microarray and quantitative reverse transcription polymerase chain reaction (qRT‐PCR) analyses have shown upregulation of genes associated with PAH, including CCAAT/enhancer binding protein β (CEBPβ), cytochrome P450 family 1 subfamily B member 1 (CYP1B1), and Fos proto‐oncogene, AP‐1 transcription factor subunit (FOS). Here, FOS is linked to pulmonary arterial hypertension.