ATCHX20 (CATION/H+ EXCHANGER 20); monovalent cation:proton antiporter. similar to ATCHX18 (cation/hydrogen exchanger 18), monovalent cation:proton antiporter [Arabidopsis thaliana] (TAIR:AT5G41610.1); similar to ATCHX19 (CATION/H+ EXCHANGER 19), monovalent cation:proton antiporter [Arabidopsis thaliana] (TAIR:AT3G17630.1); similar to ATCHX17 (CATION/H+ EXCHANGER 17), monovalent cation:proton antiporter [Arabidopsis thaliana] (TAIR:AT4G23700.1); similar to unnamed protein product [Vitis vinifera] (GB:CAO15619.1); similar to Sodium/hydrogen exchanger [Medicago truncatula] (GB:ABD32190.1); similar to hypothetical protein [Vitis vinifera] (GB:CAN