Expression of B-cell genes in venetoclax-sensitive myeloma patient samples. (A) Western blot of STAT5A, RASGRP2, BTK, and ACTIN in a subset of cell lines. (B) Heat map representing mean fluorescent intensity (MFI) of cell surface markers averaged from 3 independent experiments. Sensitive (green) and resistant (orange) cell lines are denoted by colored boxes above the heat map. (C) Scoring system for flow-based markers. (D) Application of scores to myeloma cell lines from panel B. The dashed line represents the cutoff for sensitivity vs resistance. (E) Heat map of cell surface marker expression in patient samples. The top row of green (sensitive) and orange (resistant) boxes denotes the flow-based score and prediction for venetoclax response. The second row of boxes represents the prediction from ex vivo testing.