FBLN1 and breast cancer: Thus, the ambiguous function associated with fibulin-1 in tumor-related processes has several possible explanations: posttranslational modifications, such as the proteolytic processes affecting fibulin-1 in mammary tumors; alternative splicing, which generates the different forms of fibulin-1; interaction of fibulin-1 with different components of the ECM; or even the areas where fibulin-1 is expressed [stromal vs. tumor cells; (22, 33–35)].