Methods are provided for quantifying specific proteins directly in biological samples that have been fixed in formalin by SRM/MRM assay. Such biological samples are chemically preserved and fixed wherein said biological sample is selected from tissues and cells treated with formaldehyde containing agents/fixatives including formalin-fixed tissue/cells, formalin-fixed/paraffin embedded (FFPE) tissue/cells, FFPE tissue blocks and cells from those blocks. A protein digest is prepared from the biological sample using, for example, the Liquid Tissue reagents and protocol and a designated protein is quantitated in the digest sample by the method of SRM/MRM mass spectrometry by quantitating in the protein sample at least one or more of the described peptides. The proteins that can be detected and/or quantitated are CD3D, B7H3, B7-2, STAT1, GBP1, GPNMB, CD27, CD3E, and CD8.