PER3 and neoplasm: Several genes found to be regulated by acidosis after 24 h has been described to affect functional parameter of tumor progression, such as proliferation (e.g., Gls2 [37]), cell death (e.g., Txnip, Gls2 [38, 39] tumor cell migration (e.g., Per3, Ikbke, Txnip [40–42] and adhesion (e.g., Txnip [43]) or mitochondrial activity (e.g., Txnip [44]).