MSX1 and plasma cell myeloma: For example, Kigamicin, a compound derived from actinomycetes, induces necrosis in human multiple myeloma cells by inhibition of cyclin D1, p21, p-AKT, and p-ERK [44]; and a D-amino acid-containing peptide HYD1 increases the reactive oxygen species (ROS) production, leading to necrotic cell death in multiple myeloma cells [45–47].