sentence: For example , a related VPS10P-domain receptor , sortilin , promotes oncogenic growth in breast cancer [ 50 , 51 ] but conversely attenuates EGFR signaling by enhancing its internalization and subsequent lysosomal degradation in lung cancer [ 20 ] , suggesting that the biological roles of this family of proteins may be context and cancer type specific.Our observation that heregulins upregulate SorLA and that SorLA , in turn , determines the heregulin response in BT-474 cells , alludes to a potential SorLA-dependent mechanism enabling metastatic breast cancer cells to adapt to , and colonize , the brain microenvironment .