Extraction of DNA and RNA from FFPE

DNA and RNA were extracted from FFPE material in accordance with established protocol; the process has already been described in detail in previous publications [27 (link)]. Briefly, tumor cells were isolated from formalin-fixed paraffin-embedded (FFPE) tissue slices obtained from biopsies or surgical specimens through microdissection. DNA was extracted for the VariantPlex™ assay using the Maxwell RSC 48 system (Promega, Madison, WI, USA) with the Maxwell RSC FFPE Plus DNA Kit (AS1720). For the FusionPlex™ assay, RNA was extracted using the RSC RNA FFPE Kit (Promega, AS1440). Quantification of nucleic acids was performed using a Quantus Fluorometer with the QuantiFluor ONE dsDNA System (Promega) or a Qubit device (Thermo Fisher, Waltham, MA, USA), utilizing dsDNA HS or RNA HS assays as appropriate.