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Predictive pathology is a unique addition in an otherwise predominant diagnostic focus of this atlas. In the last few decades, a large number of ‘predictive markers’ for various cancers in particular ‘breast’, ‘stomach’ and ‘lung’ among others were validated and now an integral part of standard patient care. Pathologists particularly histopathologists play a pivotal role in this exercise. Beginning with ‘oestrogen and progesterone receptor’ assessment in breast cancer, the list of such predictive markers has seen an exponential growth like HER2 testing in breast and gastric cancer, EGFR mutational analyses and ALK testing in non-small cell lung carcinoma (adenocarcinoma). Proliferative markers like Ki-67 labelling are also commonly used in a wide variety of tumours. In lymphomas, particularly ‘diffuse large B-cell lymphoma’, distinction between ‘germinal centre and activated B-cell’ phenotype is often requested, while markers like c-myc, bcl2 and bcl6 are required to distinguish double- or triple-hit lymphomas among high-grade B-cell lymphomas. Prime reason for this explosion is the specific personalized or precision treatment availability based on individualized tumour analysis, targeting or blocking the pathways fuelling the tumour growth. More recently with the approval of ‘immune checkpoint inhibitors’, testing for PD-L1 by IHC to predict usefulness of therapy is required. An important aspect of all these predictive markers is the validation of testing as well as correct interpretation or scoring as per international like ASCO/CAP guidelines. In this chapter quick reporting guidelines are provided to help pathologists to minimize any such errors by liberal use of IHC and FISH images.