IFNA1 and neoplasm: To test in vivo the ability of IFN-α to inhibit the initiating tumor capacity of MM CSCs, secondary melanospheres of A375 and MEL-1 were treated with low dose IFN-α during 72 h and after that, 500 viable cells/mL were injected into both subcutaneous flanks of 20 NSG mice for every cell line.