Immunohistochemistry was performed with EGFR, p27, Ki67, STAT3, and MAPK, as well as an H&E histopathological analysis, looking for their relationship with the response to treatment with tyrosine kinase inhibitors....We found a relationship between EGFR, Ki67, STAT3, stratum corneum, number of layers of stratum corneum, with the response to treatment, and better progression-free survival for high expression EGFR, number of layers of the stratum corneum and low expression for p27.