CPS1 and neoplasm: Furthermore, we recognized that underexpression of CPS1, the rate-limiting enzyme that regulates the first reaction of the urea cycle, was not only significantly associated with tumor progression (pT status) of IHCC but also an independent prognosticator predicting lower overall survival (OS), disease-specific survival (DSS), local recurrence-free survival (LRFS) and metastasis-free survival (MeFS) rate in patients with IHCC.