PAX5 and B-cell non-Hodgkin lymphoma: The aims of this study were (1) to classify feline lymphoma in each anatomical subtype using the World Health Organization (WHO) classification to provide information on epidemiological findings; (2) to investigate the expression and detection of B-cell lymphoma, various antibodies will be used, with the addition of PAX5, for clearer results; and (3) to gather more extensive information about feline lymphoma in Thailand, particularly in the Bangkok area.