Of particular interest is GM3 ganglioside, the simplest monosialylated ganglioside, which has been consistently implicated in tumor growth, progression, and immune recognition. GM3 has been proposed as a tumor-associated antigen in multiple malignancies for a long time. Evidence from various cancer models indicates that anti-GM3 antibodies provide an additional layer of tumor control. Increased titers of anti-GM3 IgG have been noted in malignant cell cultures and in patient samples, suggesting that both direct GM3 expression and antibody-mediated recognition contribute to shaping the tumor microenvironment.