ALT Phoenix: a generative AI framework enabling highly accurate virtual spatial transcriptomics from routine H&E. The Nest is a highly curated dataset of 79 Xenium whole slide images and 924 Xenium tissue microarray cores spanning 16 organ systems and 7 gene panels, totaling 22.2 million cell-image & cell-expression pairs. Phoenix uses a flow matching model conditioned on pathology images to generate single-cell transcriptomics.