We usually denote the origin of a mutation as either somatic or germline. This information is usually available in certain databases such as CIVIC, ClinVar, COSMIC etc. But when we come to variants that have been denoted as "Overexpression", "Upregulation" , "Methylation" etc., what would be the origin? Any leads would be very helpful. Thanks in advance.
E.G "ABCA1 is significantly overexpressed in patients at advanced stages of colorectal cancer, and its overexpression confers proliferative advantages together with caveolin‐1 dependent‐increased migratory and invasive capacities. Overexpression of ABCA1 was associated with overall survival independently of the molecular subtype of the cancer." (PMID : 30098223,Cristina Aguirre‐Portolés et al., 2018, Mol Oncol.)
Does this overexpression phenomenon arise in the germline or does it happen somatically? How do we conclude?