In the Erbb2-induced breast tumor model, Srsf3 was oncogenic in promoting breast tumor formation because all mammary glands with WT Srsf3 expression in six Erbb2 mice exhibited c-neu (Erbb2)-positive tumor foci, but none of eight Erbb2 mice with the Srsf3 KO had any detectable tumor foci in the mammary glands at the 6th month of animal age (Figure 1B). This evidence concerns the gene ERBB2 and breast neoplasm.