Although the pioneering work by Henning et al. [27] on SP/NK-1R did not provide information on squamous cell carcinomas, research results are available on the importance of alterations of this protein and its receptor in squamous cells carcinomas; in this sense, our research group have reported results in pre-malignant and malignant epithelia of the larynx and oral cavity [10,12,28]. This evidence concerns the gene TACR1 and squamous cell carcinoma.