Pathway Studio Analysis of 203 Gene Set. Out of 203 genes, 74 genes were found to be involved in direct interactions. Protein hubs which have most significant interactions (CDC2, CHEK1, CDC45L and MCM6) are marked with an asterisk (*). Although there are relatively large numbers of interactions stemming from TP53, P21 and CMYC, these proteins were not among the most statistically significant hubs. Green color indicates a gene is upregulated in melan-a relative to B16 whereas red color indicates that a gene is downregulated in melan-a relative to B16. Color intensity reflects the expression ratio.