Altered expression of GM1 and GM2 synthases in melanoma cells. Correlation with patients’ survival. (A) GM1 and GM2 synthases expression assessed by Real Time PCR in melanoma cells separated in three clusters. Grey color denotes the expression of the enzyme, white color the absence. Values are the mean ± S.D. of four independent experiments. (B) Kaplan-Meier survival analysis of patients according to GM1 synthase expression, (C) according to GM2 synthase expression, and (D) according to both GM1 and GM2 synthases expression. Survival was evaluated as time from first diagnosis.