MYL2 and neoplasm: Staining for phospho-myosin light chain 2 (pMLC2) in stromal regions (a marker of stiffness induced CAF activation and contractility) showed increased pMLC2 in gemcitabine-treated (stiffer) tumors, which was significantly decreased in combination-treated (softer) tumors (Extended Data Fig. 6d), matching the observed changes in tumor stiffnesses (Fig. 4e).