Consistently with the effects of trametinib on Id1 expression in vitro, IHC analysis revealed a downregulation of Id1 expression in CMT-167 and LLC tumor tissues in vivo (CMT167: Control: 1.12 ± 0.3038, CMT-167 TRAM: 0.04059 ± 0.0097; LLC: Control: 5.96 ± 1.617, TRAM: 2,339 ± 1.946) (Fig. 1F). This evidence concerns the gene ID1 and neoplasm.