HM13 and cancer: As they and others have noted [144], aggregation is known to correlate with the ability of metastasizing cancer cells to migrate; by the same token, aggregation should be taken into account when designing future SPP-based therapies, in which it could serve as both a hindrance (e.g., if it stops the motion entirely through steric interactions) or a help (if it allows more cargo to be transported while still permitting motion).