Further evidence for the requirement for therapies that target ERCC1-XPF comes from recent (2015-present) systematic reviews and meta-analyses that conclude that high expression of ERCC1 and/or XPF in tumors leads to poor prognoses, and low expression of ERCC1 and/or XPF in tumors leads to improved prognoses in a wide variety of different cancer types (38–48). Here, ERCC4 is linked to cancer.