EFNA1 and colorectal cancer: PCK1 and EFNA1 have been found to be involved in important life activities such as cell proliferation and apoptosis, tumor angiogenesis, malignant cell events, and invasiveness (Sadasivam et al., 2014), and their expression is upregulated in a variety of tumors [such as colorectal cancer (Shi et al., 2012)].