HSPA1B and ischemic stroke: (3) The mechanism by which RIPK1 inhibition increases lysosomal Hsp70.1B levels may be associated with an increase in Hsp70.1B transcription; this occurs via RIPK1 knockdown-mediated exacerbation of ischemic stroke-induced decreases in the cytoplasmic levels of Hsp90 and its interaction with Hsf1, which in turn promotes the nuclear translocation of Hsf1 and increases Hsp70.1B mRNA transcription.