SLC9A1 and neoplasm: Furthermore, incubation with 2 μmol/l of the specific NHE1 inhibitor DMA almost completely abrogated both basal motility and invasion and their stimulation by serum deprivation, and the potentiation by either dn-N19RhoA or ca-V12Rac1, supporting our previous observation [6] and the findings of others [7-9] that the NHE1 plays a fundamental role in tumour cell motility and invasion.