A similar expression pattern is also observed in other tumor types: in colorectal cancer (CRC), PKD1 is expressed only in normal colon cells, PKD2 is the dominant isoform at the transcriptional level in tumor samples, and both PKD2 and PKD3 are highly expressed in CRC cell lines (Wei et al., 2014). This evidence concerns the gene PRKD3 and colorectal carcinoma.