ALDH1A1 and neoplasm: Moreover, co-expression of SALL4 and ALDH1A1 is associated with more aggressive tumor behavior, advanced disease, and poor disease-specific survival (DSS), or progression-free survival (PFS) in SOC cases, and higher co-expression of SALL4/ALDH1A1 was found as an independent prognostic factor for PFS [196].