The antitumor mechanisms of fucoidans in these tumor cells (e.g., A549, MCF-7) include cell cycle arrest at the sub-G1/G1 phase [79,80,81,82], caspase-dependent apoptosis [80,81,83], regulation of specific apoptotic proteins (e.g., poly [ADP-ribose] polymerase 1 (PARP1) [84,85,86], protein kinase RNA-like endoplasmic reticulum kinase (PERK), B-cell lymphoma 2 (Bcl-2) [84], BAX [84,87], and caspases -3, -8, and -9 [80,84,86]). The gene discussed is PARP1; the disease is neoplasm.