Efficacy of tyrosine kinase inhibitors (TKIs) in clinical practice is related to partial tumor response with improvement in signs and achievement of stable disease [21,22,23]; However, to the authors’ knowledge, the association between the use of TKIs and the expression of PDGFRβ has been only marginally investigated in canine AGASACs and its lymph node metastases [16,18]. Here, PDGFRB is linked to neoplasm.