L1CAM and melanoma: Together, our findings inform the following working model: in the melanoma, particularly the invasive front of the primary tumor, androgen-activated AR transcriptionally upregulates FUT4, which in turn fucosylates L1CAM and disrupts N-cadherin-mediated AJ structures that are required for AR-FUT4-enhanced invasiveness and metastatic spread of melanoma cells (Fig. 5g).