Similar results were observed in the current studies when C57BL/6.Psl1Adba mice were initiated with 100 nmol DMBA and promoted twice weekly with either 6.8 or 13.6 nmol of TPA (Table 1 and Table 2), further supporting the previous conclusion that the genes underlying the Psl1 locus have an effect on tumor promotion rather than tumor initiation. Here, SPPL2B is linked to neoplasm.