MAPK3 and neoplasm: We then crossed SPC-Cre-ERT2 or CCSP-CreERT2 allele with either Kras or Kras/Cdc42 mice to generate SPC-Cre-ERT2/Kras (SK)34, SPC-Cre-ERT2/Kras/Cdc42 (SKC), CCSP-Cre-ERT2/Kras (CK) and CCSP-Cre-ERT2/Kras/Cdc42 (CKC) mice and performed the detailed tumor analyses after tamoxifen treatment (Fig. 4c).