Levels of PTK6 increase under hypoxic conditions due to direct transcriptional regulation of PTK6 gene by hypoxia inducible transcription factors (HIFs) (Regan Anderson et al. 2013). PTK6 protein levels are also rapidly stabilized in hypoxic conditions in a HIF-independent manner (Pires et al. 2014). It has also been shown that PTK6 is ubiquitinated in normoxic conditions by a so far unknown E3 ligase (Pires et al. 2014).