Algorithm 2 Pipeline of the maximum flow-based drug repurposing.

Input: PPI = all the PPIs, FDA_DT = all the FDA approved DTs in PPIs network, DTI = DTIs for FDA_DT, RG = risk genes, W = flow capacity of edges. Output: CD = candidate drugs for repurposing for the treatment of breast cancer.   1. FOR i = 1 to length [PPI]:     a. Calculate flow capacity of the edge using Equation (1):      C[i] = TOMSimilarity (PPI[i])   2. CREATE two dummy nodes:     a. source dummy node = SDN and destination dummy node = DDN   3. FOR i = 1 to length [FDA_DT]:     a. Index = length [PPI] + 1     b. CONNECT SDN to FDA_DT[i] and add this interaction in PPI[index]     c. W[index] = sum of the capacities of the outgoing edges from PPI[index]   4. FOR i = 1 to the length of RG:     a. Index = length of PPI + 1     b. CONNECT RG[i] to DDN and add this interaction in PPI[index]     c. C[index] = sum of the capacities of the incoming edges from PPI[index]   5. The nodes in PPIs and their associated outgoing flow value = Push-Relabel_MaximumFlow_Algorithm (PPI, C, SDN, DDN)   6. prioritized_DTs = sort the nodes in PPI in decreasing order of their outgoing flows   7. CD = sort drugs in DTI using prioritized_DTs