Fig. 2

Immunohistochemical staining pictures related to microsatellite instability are presented as follows: A depict positive staining for MutL homolog 1 (MLH1) and B&C depict positive staining for MutS Homolog 2 (MSH2) and MutS Homolog 6 (MSH6) mutations, while D show case negative staining for mutations of Postmeiotic segregation increased 2 (PMS2). Edge-enhanced and bright-field imaging (E&F Imaging) of H&E staining. It is worth mentioning that in the analysis of immunohistochemical slides of microsatellite samples, the color ability of tumoral cell nuclei with chromogen indicates the absence of mutation in the investigated marker and is considered negative from the point of view of the specific antibody. In other words, the absovation of cells not stained with chromogen indicates a disruption in the DNA mismatch repair (MMR) system. MMR is a system for recognizing and repairing erroneous insertion, deletion, and mis-incorporation of bases that can arise during DNA replication and recombination, as well as repairing some forms of DNA damage G: Negative and H: Positive cytoplasmic staining image for Eh-lectin light chain antigen. I: H&E slide of adenocarcinoma of colorectal