Exploration of other gender-based interactions of BMI and serum creatinine with co-morbidities, lifestyle habits, co-medications for co-morbidities, BRAF V600, NRAS mutations, prior therapies for melanoma (targeted therapy, immunotherapy, chemotherapy and radiation) and interaction of BMI with clinical chemistry parameters, disease severity and other demographics did not provide plausible strong alternative explanations for gender-based difference (Additional file 1: Text, Figures S3-S5 and Table S1). The gene discussed is NRAS; the disease is melanoma.