Table 1

Possible experiments to investigate paradox associated with sarcomas and Millipore filters

Question

Proposed experiment

Rationale

What aspect of the implant is responsible for sarcomas?

2 × 2 × 2 × 2 factorial design involving surface area, roughness, electrostatic charge, pore size

A factorial design allows investigation of many factors at once.

How does the implant affect cellular changes?

Primary study: no implant versus small pore implant that induces sarcoma

Looking for salient differences in gene expression using multiple random validation and signatures with few genes

Secondary study: no implant versus large pore implant that does not induce sarcoma

Control study to determine if differences in gene expression could reliably be associated with histological changes

Baker and Kramer BMC Cancer 2007 7:151   doi:10.1186/1471-2407-7-151