Specifically, in terms of the evaluated markers, ALDH1 immunostaining at the tumour centre areas typically manifested as sporadic cytoplasmic staining, predominantly encircling corneal pearls (Fig. 1D), whereas it was more pronounced in the expression observed in the more invasive cells found within lymphatic emboli (Fig. 1E) and metastatic tumour cells (Fig. 1F). This evidence concerns the gene ALDH1A1 and neoplasm.