SPHK1 and colorectal cancer: For example, inhibiting SPHK1 using siRNA or pharmacological inhibitors significantly decreased proliferation, migration and angiogenesis in epithelial ovarian carcinoma [16], the SPHK1 inhibitor SK1-I regulated the ceramide-sphinogosine-S1P balance, suppressed proliferation and induced apoptosis in cholangiocarcinoma [17], and SPHK1 has been shown to be overexpressed and overactivated and to contribute to cetuximab resistance in human colorectal cancer models [18].