To investigate the functional consequences of In1-ghrelin variant expression and the regulation of In1-ghrelin transcript, we employed an in vitro approach using a breast cancer cell line, MDA-MB-231, which expresses In1-ghrelin variant, GOAT and GHSR1b transcripts at high levels while virtually lack the expression of native-ghrelin and GHSR1a (table S4), a pattern that is reminiscent of that observed in primary breast cancers. Here, GHSR is linked to breast cancer.