Hematoxylin and Eosin (H&E) staining was done according to the previously described method [17 (link),18 ]. The slides were incubated with Harris hematoxylin for 10 seconds, washed, treated with eosin (Sigma Aldrich Co., St. Louis, MO, USA) for 5 seconds, and washed again. After drying, the slides were dehydrated by soaking in ethanol and xylene, and sealed with Permount (Thermo Fisher Scientific). Images were captured using an Image Analysis System (Leica Microsystems, Wetzlar, Germany).