BCL2L1 and cancer: However, the role of HnRNP H1 in cancer development is still complicated by its ability to upregulate anti-apoptotic heterodimers (MADD30) and pro-apoptotic spliceosomes (Bcl-xS), such as the increase in the oncogene Δ16HER2 variant observed following knockdown of HnRNP H1, suggesting that deletion of this splicing factor may lead to a more oncogenic phenotype (36).