Mechanisms of action were turned into feature vectors as follows: There were 821 unique mechanisms of action for the original 1784 PANC1 screening compounds. Each mechanism of action was encoded as an element in a vector of length 821, and the presence or absence of a mechanism of action for each combination was represented by 1 and 0, respectively. For instance, a combination with two distinct mechanisms of action would be encoded as a vector that has two elements set to 1 and the rest of them set to 0.