Figure 2. The screening of key genes in the melanoma pathway. (A) The volcano map shows differential genes between primary and metastatic melanoma. The red points represent up-regulated genes and the blue ones represent down-regulated genes in the metastatic samples. The top 10 up- and down-regulated genes with the highest significance were labeled. (B) The Venn diagram shows screening conditions for key genes. (C) The expression levels of 4 key genes in melanoma. (D) The expression levels of 4 key genes in normal and melanoma tissues. * p-value < 0.05, ** p-value < 0.01, *** p-value < 0.001.