S20-218 First-in-class isoform-specific aldehyde dehydrogenase (ALDH1B1 and ALDH1A3) inhibitors for cancer Every year, 1.4 million new cases are reported for colorectal cancer but existing treatments are not effective. This represents an estimated $1 billion market annually in the US. James Chen Toni Kline Alison Ondrus Cody Marshall Marisa Hom Zhiping Feng