If the dupα7 nAChR subunit expressed in these tumors plays a similar role to that found in Xenopus oocytes [26], it is possible that deficient dupα7 subunit expression facilitates the oncogenic process mediated by α7-nAChRs, especially in SQC-L where overexpression of this nAChR subtype appears to be determinant to cancer progression. This evidence concerns the gene CHRNA4 and cancer.