HV1-IN-2 (Compound 14c) is a human voltage-gated proton channel (HV1) inhibitor with an IC50 of 2.14 μM. HV1-IN-2 has a potent anticancer activity with significant antiproliferative effects against THP-1 and MCF-7 cells. HV1-IN-2 can be used for cancers research, such as colorectal tumours, leukaemia, and breast cancer[1].