CCL18 and melanoma: Similarly, four 1-gene signatures with classification accuracy better that 71% are predicted to be urine excretory, CCL18 (73.2% on training and 71.4% on testing set), HEXB (73.2% on training and 71.4% on testing set), IFI30 (73.2% on training and 71.4% on testing set) and STC1 (73.2% on training and 71.4% on testing), by using our prediction program [26], suggesting the potential feasibility in identifying diagnostic markers for melanoma through urine tests.