Ddx5 was increased in the whole skin lesions of MC903- or IMQ-treated Cd93–/– mice compared with their wild-type counterparts (Fig. 3a and Extended Data Fig. 5a), along with fewer plaques on the ears or dorsal skin (Extended Data Fig. 5b) and reduced expression of Il4, Il13, Ccl11, Ccl17 and Ccl22 (Fig. 3b) or Cxcl1, Cxcl2, Ccl20, Il23, Il17a and Il36γ (Extended Data Fig. 5c). This evidence concerns the gene IL4 and neoplasm.