Notably, excess hyaluronan production by HAS2 overexpression drives EMT by induction of Snail and Twist.8 Our data demonstrate that HAS2, hyaluronan and USP17 were expressed at high levels in pre-neoplastic lesions and acinar ADC (Figure 7a and Table 1), and at higher levels in metastatic breast cancer and lung cancer cell lines compared to normal cells (Figure 6a), suggesting that USP17-mediated stabilization of HAS2 resulting in increased hyaluronan synthesis, promotes non-small cell lung cancer and breast cancer tumor progression. This evidence concerns the gene USP17L2 and AIDS dementia complex.