“…Although PDX results are often clinically relevant, to decrease animal distress, scientists are tasked to find alternative methods that replace, reduce, and refine the use of animals [ 50 ]. Consequently, other 3D cell-based assays are widely accepted and have proven to be versatile; they cut time, animal use, and cost, while facilitating more replicates and high-throughput endpoints [ 51 , 52 , 53 , 54 , 55 , 56 ]. Ideally, such platforms would include cancer-specific architectures, relevant biomechanical components, and cellular interactions (stroma-cancer and cell-extracellular matrix) found in patient tumors that assist in considering their inherent heterogeneity.…”