MYC and invasive carcinoma: While cathepsin L-deficiency had no profound effect on pancreatic tissue pathology in the absence of MycERTAM activation (Fig 4A), or following three-day exposure to TAM (Fig 3B) when compared to cathepsin L wild-type (WT) counterparts, the formation of Myc-induced invasive carcinomas following two-week exposure to TAM was significantly impaired by the absence of cathepsin L (Fig 4A).