cc-TDI announces a new tool for collaboration – a “tissue microarray” (TMA) of 65 mouse soft tissue sarcomas with varying cell-of-origin and mutational profile. This includes rhabdomyosarcoma and non-rhabdomyosarcoma soft tissue tumors. By having so many mouse tumors on a single microscope slide, and knowing how the genetically-engineered mutations and cell of origin affect the proteins present in a tumor, new ideas for therapies based on tumor cell memory of the cell from which it came can quickly be generated. This approach is detailed in our recent Genes & Development paper, Lineage of origin in rhabdomyosarcoma informs pharmacological response. These TMAs have been deposited in a public repository at the COG Biorepository-associated BioPathology Center, and are available at a nominal fee with a very short application. We have already made these TMAs available to almost 2 dozen sarcoma investigators worldwide. To obtain a TMA, please contact firstname.lastname@example.org or Natalie.Beeler@nationwidechildrens.org.