A significantly higher expression of RBMS3 in more aggressive types of tumors characterized by the lack of estrogen-receptor expression, and in the case of the SK-BR-3 cell line the presence of the HER2 receptor, may indicate that a certain level of RBMS3 expression is necessary for specific types of cancer progression and their ability to create metastasis [20,25]. This evidence concerns the gene RBMS3 and cancer.