The development of genetic markers is complex and costly in species with little pre-existing genomic information.
Measurement of urinary clearance using exogenous markers is complex, expensive, and difficult to perform in routine clinical practice and cohort studies.
Study design of Q-marker is complex system for quality assessment and production process control of CM products with transitivity and traceability.
Clinical validation of a tumor marker is complex, time-consuming, and expensive; careful planning at every stage is therefore essential to avoid a waste of resources.
Identification of a suitable counterselection marker is complex and often organism specific (11); however, it is often assumed that isolating mutants using two-step allele exchange is extremely laborious without a counterselection marker due to the low frequency at which the second recombination event occurs (11).
However, we acknowledge that studies to construct and validate array-based prognostic and predictive 'markers' are complex.
In our judgment, the issues in reporting predictive marker studies are complex and different enough from those of prognostic marker studies that we are not willing to claim that these guidelines give predictive marker studies adequate coverage, although we believe that most of the guidance is relevant to such studies too.
Secondly, the procedures for developing such markers are difficult, complex, and high-cost.
37, 57, 58 Serologic markers are a complex surrogate of influenza vaccine effectiveness, and notably when birth cohorts are compared.
In contrast, the clinical studies required to demonstrate the clinical validation of predictive markers are more complex.
Clearly, the relationships between single and combination drug treatments and markers of ER stress/UPR signalling are complex and not easily interpretable in relation to the progression of cell death.
